public static bool klv_init(bilist ***lbucket_ptr, /* space for left bucket sorts */
bilist ***rbucket_ptr, /* space for right bucket sorts */
bilist **llistspace, /* space for elements of linked lists */
bilist **rlistspace, /* space for elements of linked lists */
int **ldvals, /* change in separator for left moves */
int **rdvals, /* change in separator for right moves */
int nvtxs, /* number of vertices in the graph */
int maxchange /* maximum change by moving a vertex */
)
{
int sizeb; /* size of set of buckets */
int sizel; /* size of set of pointers for all vertices */
/* Allocate appropriate data structures for buckets, and listspace. */
sizeb = (2 * maxchange + 1) * sizeof(bilist *);
*lbucket_ptr = (bilist **)Marshal.AllocHGlobal(sizeb);
*rbucket_ptr = (bilist **)Marshal.AllocHGlobal(sizeb);
*ldvals = (int *)Marshal.AllocHGlobal((nvtxs + 1) * sizeof(int));
*rdvals = (int *)Marshal.AllocHGlobal((nvtxs + 1) * sizeof(int));
sizel = (nvtxs + 1) * sizeof(bilist);
*llistspace = (bilist *)Marshal.AllocHGlobal(sizel);
*rlistspace = (bilist *)Marshal.AllocHGlobal(sizel);
return(*lbucket_ptr == null || *rbucket_ptr == null || *ldvals == null || *rdvals == null ||
*llistspace == null || *rlistspace == null);
}
private static void p1bucket(bilist **bucket, /* buckets holding bucket list */
bilist *lptr, /* elements within bucket */
int maxdeg /* maximum degree of a vertex */
)
{
bilist *bptr; /* loops through list at a bucket */
int val; /* element in a bucket */
int size; /* array spacing */
int i; /* loop counter */
size = (int)(&(lptr[1]) - &(lptr[0]));
for (i = 2 * maxdeg; i >= 0; i--)
{
if (bucket[i] != null)
{
Console.Write(" Bucket {0:d}:", i - maxdeg);
for (bptr = bucket[i]; bptr != null; bptr = bptr->next)
{
val = ((int)(bptr - lptr)) / size;
Console.Write(" {0:d}", val);
}
Console.WriteLine();
}
}
}
/*static void p1bucket();*/
private static void pbuckets(bilist ****buckets, /* pointers to bucket lists */
bilist **listspace, /* elements within buckets */
int maxdeg, /* maximum degree of a vertex */
int nsets /* number of sets being divided into */
)
{
bilist *lptr; /* points to correct listspace */
int i, j; /* loop counter */
Console.WriteLine();
for (i = 0; i < nsets; i++)
{
for (j = 0; j < nsets; j++)
{
if (i != j)
{
Console.WriteLine("For transition {0:d} -> {1:d}", i, j);
if (j > i)
{
lptr = listspace[j - 1];
}
else
{
lptr = listspace[j];
}
p1bucket(buckets[i][j], lptr, maxdeg);
Console.WriteLine();
}
}
}
Console.WriteLine();
}
public static void movebilist(bilist *lptr, /* ptr to element to move */
bilist **oldlist, /* head of list to remove it from */
bilist **newlist /* head of list to add it to */
)
/* Move an element from a old bidirectional list to new one. */
{
removebilist(lptr, oldlist);
add2bilist(lptr, newlist);
}
/* Note: bi-directional lists aren't assumed to be sorted. */
private static void add2bilist( /* add val to unsorted list */
bilist *lptr, /* element to add */
bilist **list /* list added to */
)
{
lptr->next = *list;
if (*list != null)
{
(*list)->prev = lptr;
}
lptr->prev = null;
*list = lptr;
}
static void free_kl(
/* Free everything malloc'd for KL. */
bilist ****buckets, /* space for bucket sorts */
bilist **listspace, /* space for all bidirectional elements */
int **dvals, /* change in penalty for each possible move */
int **tops /* starting dval for each type of move */
)
{
Marshal.FreeHGlobal((IntPtr)dvals);
Marshal.FreeHGlobal((IntPtr)tops);
Marshal.FreeHGlobal((IntPtr)listspace[0]);
Marshal.FreeHGlobal((IntPtr)buckets[0][1]);
Marshal.FreeHGlobal((IntPtr)listspace);
Marshal.FreeHGlobal((IntPtr)buckets);
}
public static void free_klv(
/* Free everything malloc'd for KLV. */
bilist **lbuckets, /* space for bucket sorts */
bilist **rbuckets, /* space for bucket sorts */
bilist *llistspace, /* space for all bidirectional elements */
bilist *rlistspace, /* space for all bidirectional elements */
int *ldvals, /* change in penalty for each possible move */
int *rdvals /* change in penalty for each possible move */
)
{
Marshal.FreeHGlobal((IntPtr)rlistspace);
Marshal.FreeHGlobal((IntPtr)llistspace);
Marshal.FreeHGlobal((IntPtr)rdvals);
Marshal.FreeHGlobal((IntPtr)ldvals);
Marshal.FreeHGlobal((IntPtr)rbuckets);
Marshal.FreeHGlobal((IntPtr)lbuckets);
}
private static void removebilist(bilist *lptr, /* ptr to element to remove */
bilist **list /* head of list to remove it from */
)
/* Remove an element from a bidirectional list. */
{
if (lptr->next != null)
{
lptr->next->prev = lptr->prev;
}
if (lptr->prev != null)
{
lptr->prev->next = lptr->next;
}
else
{
*list = lptr->next;
}
}
/* Idea:
* 'buckets[i][j]' is a set of buckets to sort moves from i to j.
* listspace[i] is space for lists in buckets[i][j].
* Loop through all nonequal pairs [i][j], taking the first element
* in each list. Compare them all to find the largest allowed move.
* Make that move, and save it in movelist.
*/
public static void bucketsort1(vtx_data **graph, /* graph data structure */
int vtx, /* vertex being added to lists */
bilist ****buckets, /* array of lists for bucket sort */
bilist **listspace, /* list data structure for each vertex */
int **dvals, /* d-values for each vertex for removing */
int *sets, /* processor each vertex is assigned to */
float *[] term_wgts, /* weights for terminal propagation */
int maxdval, /* maximum possible dvalue for a vertex */
int nsets, /* number of sets being divided into */
int [][] hops, /* hop cost between sets */
bool useEdgeWeights /* are edge weights being used? */
)
{
bilist *lptr = null; /* pointer to an element in listspace */
float * ewptr = null; /* loops through edge weights */
int * edges = null; /* edge list for a vertex */
int myset; /* set that current vertex belongs to */
int newset; /* set current vertex could move to */
int set; /* set that neighboring vertex belongs to */
int weight; /* edge weight for a particular edge */
float tval; /* terminal propagation value */
int val; /* terminal propagation rounded value */
double cut_cost; /* relative cut/hop importance */
double hop_cost; /* relative hop/cut importance */
int myhop; /* hops associated with current vertex */
int j, l; /* loop counters */
/* Compute d-vals by seeing which sets neighbors belong to. */
cut_cost = hop_cost = 1;
if (term_wgts[1] != null)
{
if (CUT_TO_HOP_COST > 1)
{
cut_cost = CUT_TO_HOP_COST;
}
else
{
hop_cost = 1.0 / CUT_TO_HOP_COST;
}
}
weight = (int)(cut_cost + .5);
myset = sets[vtx];
/* Initialize all the preference values. */
if (term_wgts[1] != null)
{
/* Using terminal propagation. */
if (myset == 0) /* No terminal value. */
{
for (newset = 1; newset < nsets; newset++)
{
tval = (term_wgts[newset])[vtx];
if (tval < 0)
{
val = (int)(-tval * hop_cost + .5);
val = -val;
}
else
{
val = (int)(tval * hop_cost + .5);
}
dvals[vtx][newset - 1] = val;
}
}
else
{
tval = -(term_wgts[myset])[vtx];
if (tval < 0)
{
val = (int)(-tval * hop_cost + .5);
val = -val;
}
else
{
val = (int)(tval * hop_cost + .5);
}
dvals[vtx][0] = val;
l = 1;
for (newset = 1; newset < nsets; newset++)
{
if (newset != myset)
{
tval = (term_wgts[newset])[vtx] - (term_wgts[myset])[vtx];
if (tval < 0)
{
val = (int)(-tval * hop_cost + .5);
val = -val;
}
else
{
val = (int)(tval * hop_cost + .5);
}
dvals[vtx][l] = val;
l++;
}
}
}
}
else
{
for (j = 0; j < nsets - 1; j++)
{
dvals[vtx][j] = 0;
}
}
/* First count the neighbors in each set. */
edges = graph[vtx]->edges;
if (useEdgeWeights)
{
ewptr = graph[vtx]->ewgts;
}
for (j = graph[vtx]->nedges - 1; j != 0; j--)
{
set = sets[*(++edges)];
if (set < 0)
{
set = -set - 1;
}
if (useEdgeWeights)
{
weight = (int)(*(++ewptr) * cut_cost + .5);
}
myhop = hops[myset][set];
l = 0;
for (newset = 0; newset < nsets; newset++)
{
if (newset != myset)
{
dvals[vtx][l] += weight * (myhop - hops[newset][set]);
l++;
}
}
}
/* Now add to appropriate buckets. */
l = 0;
for (newset = 0; newset < nsets; newset++)
{
if (newset != myset)
{
lptr = listspace[l];
add2bilist(&lptr[vtx], &buckets[myset][newset][dvals[vtx][l] + maxdval]);
++l;
}
}
}
/* Idea:
* 'buckets[i][j]' is a set of buckets to sort moves from i to j.
* listspace[i] is space for lists in buckets[i][j].
* Loop through all nonequal pairs [i][j], taking the first element
* in each list. Compare them all to find the largest allowed move.
* Make that move, and save it in movelist.
*/
/* Routine slightly streamlined for case with only two sets. */
public static void bucketsorts_bi(vtx_data **graph, /* graph data structure */
int nvtxs, /* number of vertices */
bilist ****buckets, /* array of lists for bucket sort */
bilist **listspace, /* list data structure for each vertex */
int **dvals, /* d-values for each vertex for removing */
int *sets, /* processor each vertex is assigned to */
float *[] term_wgts, /* weights for terminal propagation */
int maxdval, /* maximum possible dvalue for a vertex */
int nsets, /* number of sets being divided into */
bool parity, /* work in forward or backward direction? */
int [][] hops, /* hop cost between sets */
int *bspace, /* indices for randomly ordering vtxs */
int list_length, /* number of values in bspace to work with */
int npass, /* which pass through KL is this? */
bool useEdgeWeights /* are edge weights being used? */
)
{
bilist **bptr = null; /* loops through set of buckets */
bilist * lptr = null; /* pointer to an element in listspace */
float * ewptr = null; /* loops through edge weights */
float * twptr = null; /* weights for terminal propagation */
int * bsptr = null; /* loops through bspace */
int * edges = null; /* edge list for a vertex */
int myset; /* set current vertex belongs to */
int other_set; /* set current vertex doesn't belong to */
int set; /* set that neighboring vertex belongs to */
int weight; /* edge weight for a particular edge */
int vtx; /* vertex in graph */
int val; /* terminal propagation rounded value */
double cut_cost; /* relative cut/hop importance */
double hop_cost; /* relative hop/cut importance */
int myhop; /* hops associated with current vertex */
int i, j; /* loop counters */
/* For each vertex, compute d-values for each possible transition. */
/* Then store them in each appropriate bucket. */
if (npass == 1 || !KL_UNDO_LIST || list_length == nvtxs)
{
/* Empty all the buckets. */
/* Last clause catches case where lists weren't undone. */
bptr = buckets[0][1];
for (i = nsets * (nsets - 1) * (2 * maxdval + 1); i != 0; i--)
{
*bptr++ = null;
}
}
/* Randomize the order of the vertices */
if ((KL_UNDO_LIST && list_length == nvtxs) || !KL_UNDO_LIST)
{
list_length = nvtxs;
bsptr = bspace;
if (parity)
{
for (i = 1; i <= nvtxs; i++)
{
*bsptr++ = i;
}
}
else
{
for (i = nvtxs; i != 0; i--)
{
*bsptr++ = i;
}
}
}
if (KL_RANDOM)
{
randomize(bspace - 1, list_length);
}
/* Now compute d-vals by seeing which sets neighbors belong to. */
cut_cost = hop_cost = 1;
if (term_wgts[1] != null)
{
if (CUT_TO_HOP_COST > 1)
{
cut_cost = CUT_TO_HOP_COST;
}
else
{
hop_cost = 1.0 / CUT_TO_HOP_COST;
}
}
weight = (int)(cut_cost + .5);
bsptr = bspace;
twptr = term_wgts[1];
for (i = 0; i < list_length; i++) /* Loop through vertices. */
{
vtx = *bsptr++;
myset = sets[vtx];
other_set = myset == 0 ? 1 : 0;
/* Initialize all the preference values. */
if (twptr != null)
{
/* Using terminal propagation. Round to integer value. */
if (twptr[vtx] < 0)
{
val = (int)(-twptr[vtx] * hop_cost + .5);
val = -val;
}
else
{
val = (int)(twptr[vtx] * hop_cost + .5);
}
if (myset == 0)
{
dvals[vtx][0] = val;
}
else
{
dvals[vtx][0] = -val;
}
}
else
{
dvals[vtx][0] = 0;
}
/* First count the neighbors in each set. */
edges = graph[vtx]->edges;
if (useEdgeWeights)
{
ewptr = graph[vtx]->ewgts;
}
for (j = graph[vtx]->nedges - 1; j != 0; j--)
{
set = sets[*(++edges)];
if (set < 0)
{
set = -set - 1;
}
if (useEdgeWeights)
{
weight = (int)((*(++ewptr)) * cut_cost + .5);
}
myhop = hops[myset][set];
dvals[vtx][0] += weight * (myhop - hops[other_set][set]);
}
/* Now add to appropriate buckets. */
lptr = listspace[0];
add2bilist(&lptr[vtx], &buckets[myset][other_set][dvals[vtx][0] + maxdval]);
}
}
public static void bucketsortsv(vtx_data **graph, /* graph data structure */
int nvtxs, /* number of vertices */
bilist **lbuckets, /* array of lists for bucket sort */
bilist **rbuckets, /* array of lists for bucket sort */
bilist *llistspace, /* list data structure for each vertex */
bilist *rlistspace, /* list data structure for each vertex */
int *ldvals, /* d-values for each vertex for removing */
int *rdvals, /* d-values for each vertex for removing */
int *sets, /* processor each vertex is assigned to */
int maxdval, /* maximum possible dvalue for a vertex */
bool parity, /* work in forward or backward direction? */
int *bspace, /* indices for randomly ordering vtxs */
int list_length /* number of values in bspace to work with */
)
{
bilist **lbptr; /* loops through set of buckets */
bilist **rbptr; /* loops through set of buckets */
int * bsptr; /* loops through bspace */
int * edges; /* edge list for a vertex */
int left_weight; /* my neighbors in 0 set */
int right_weight; /* my neighbors in 1 set */
int vtx; /* vertex in graph */
int neighbor; /* neighbor of vertex */
int set; /* set that neighboring vertex belongs to */
int i, j; /* loop counters */
/* For each vertex, compute d-values and store in buckets. */
/* Empty all the buckets. */
rbptr = lbuckets;
lbptr = rbuckets;
for (i = (2 * maxdval + 1); i != 0; i--)
{
*lbptr++ = null;
*rbptr++ = null;
}
/* Randomize the order of the vertices */
if ((KL_UNDO_LIST && list_length == nvtxs) || (!KL_UNDO_LIST && !KL_RANDOM) || list_length == 0)
{
/* Don't need to reoder if about to randomize. */
list_length = nvtxs;
bsptr = bspace;
if (parity)
{
for (i = 1; i <= nvtxs; i++)
{
*bsptr++ = i;
}
}
else
{
for (i = nvtxs; i != 0; i--)
{
*bsptr++ = i;
}
}
}
if (KL_RANDOM)
{
randomize(bspace - 1, list_length);
}
/* Now compute d-vals by seeing which sets neighbors belong to. */
bsptr = bspace;
for (i = 0; i < list_length; i++)
{
/* Loop through vertices. */
vtx = *bsptr++;
if (sets[vtx] == 2)
{
/* Only worry about separator vertices. */
/* Initialize all the preference values. */
left_weight = right_weight = 0;
/* First count the neighbors in each set. */
edges = graph[vtx]->edges;
for (j = graph[vtx]->nedges - 1; j != 0; j--)
{
neighbor = *(++edges);
set = sets[neighbor];
if (set < 0)
{
set = -set - 1;
}
if (set == 0)
{
left_weight += graph[neighbor]->vwgt;
}
else if (set == 1)
{
right_weight += graph[neighbor]->vwgt;
}
}
ldvals[vtx] = graph[vtx]->vwgt - right_weight;
rdvals[vtx] = graph[vtx]->vwgt - left_weight;
/* Now add to appropriate buckets. */
add2bilist(&llistspace[vtx], &lbuckets[ldvals[vtx] + maxdval]);
add2bilist(&rlistspace[vtx], &rbuckets[rdvals[vtx] + maxdval]);
}
}
}
public static void make_bndy_list(vtx_data **graph, /* data structure for graph */
bilist *movelist, /* list of vtxs to be moved */
bilist ****buckets, /* array of lists for bucket sort */
bilist **listspace, /* list data structure for each vertex */
int *sets, /* processor each vertex is assigned to */
int nsets, /* number of sets divided into */
int *bspace, /* list of active vertices for bucketsort */
int **tops, /* top of each set of buckets */
int **bndy_list /* list of boundary vertices returned */
)
{
bilist *bptr; /* loops through bspace */
int vtx; /* vertex that was moved */
int set; /* set a vertex is in */
int list_length; /* number of active vertices */
int bndy_length; /* number of vertices actually on boundary */
int size; /* array spacing */
int i, j, k; /* loop counters */
/* First push all the moved vertices onto list, so they can be flagged. */
/* They've already been removed from buckets, so want to avoid them. */
size = (int)(&(listspace[0][1]) - &(listspace[0][0]));
bptr = movelist;
list_length = 0;
while (bptr != null)
{
vtx = ((int)(bptr - listspace[0])) / size;
bspace[list_length++] = vtx;
bptr = bptr->next;
}
/* Now get all the vertices still in the bucket lists. */
for (k = tops[0][1]; k >= 0; k--)
{
bptr = buckets[0][1][k];
while (bptr != null)
{
vtx = ((int)(bptr - listspace[0])) / size;
bspace[list_length++] = vtx;
bptr = bptr->next;
}
}
for (i = 1; i < nsets; i++)
{
for (k = tops[i][0]; k >= 0; k--)
{
bptr = buckets[i][0][k];
while (bptr != null)
{
vtx = ((int)(bptr - listspace[0])) / size;
bspace[list_length++] = vtx;
bptr = bptr->next;
}
}
}
/* Now that list is constructed, go reconstruct all the set numbers. */
bndy_length = 0;
for (i = 0; i < list_length; i++)
{
vtx = bspace[i];
set = sets[vtx];
for (j = 1; j < graph[vtx]->nedges; j++)
{
if (sets[graph[vtx]->edges[j]] != set)
{
bspace[bndy_length++] = vtx;
break;
}
}
}
/* Finally, copy boundary vertices into boundary list. */
*bndy_list = (int *)Marshal.AllocHGlobal((bndy_length + 1) * sizeof(int));
for (i = 0; i < bndy_length; i++)
{
(*bndy_list)[i] = bspace[i];
}
(*bndy_list)[bndy_length] = 0;
}
private static void p1bucket(bilist **a, bilist *b, int c)
{
throw new NotImplementedException("I couldn't find the implementation for this in Chaco source.");
}
/*
* Keep guys moved in and guys moving out of separator.
* To restore, move all undesirable guys back.
* (1) guys moved out of separator get put back in.
* (2) guys moved into separator (bspace) get put back.
* Note: Should be done in this order.
* Note: No neighbors need be considered.
* (3) To clear dvals, I should compute touch all guys that
* were ever in separator (bspace) and their neighbors.
*/
public static bool nway_klv(vtx_data **graph, /* data structure for graph */
int nvtxs, /* number of vtxs in graph */
bilist **lbuckets, /* array of lists for bucket sort */
bilist **rbuckets, /* array of lists for bucket sort */
bilist *llistspace, /* list data structure for each vertex */
bilist *rlistspace, /* list data structure for each vertex */
int *ldvals, /* d-values for each transition */
int *rdvals, /* d-values for each transition */
int *sets, /* processor each vertex is assigned to */
int maxdval, /* maximum d-value for a vertex */
double[] goal, /* desired set sizes */
int max_dev, /* largest allowed deviation from balance */
int **bndy_list, /* list of vertices on boundary (0 ends) */
double[] weightsum /* sum of vweights in each set (in and out) */
)
{
bilist **to_buckets; /* buckets I'm moving to */
bilist **from_buckets; /* buckets I'm moving from */
bilist * to_listspace; /* list structure I'm moving to */
bilist * from_listspace; /* list structure I'm moving from */
bilist * out_list; /* list of vtxs moved out of separator */
int * to_dvals; /* d-values I'm moving to */
int * from_dvals; /* d-values I'm moving from */
int * bspace; /* list of active vertices for bucketsort */
int * edges; /* edge list for a vertex */
int * edges2; /* edge list for a vertex */
int * bdy_ptr; /* loops through bndy_list */
double total_weight; /* weight of all vertices */
double partial_weight; /* weight of vertices not in separator */
double ratio; /* fraction of weight not in separator */
double time; /* timing parameter */
double delta0; /* largest negative deviation from goal size */
double delta1; /* largest negative deviation from goal size */
double left_imbalance = 0.0; /* imbalance if I move to the left */
double right_imbalance; /* imbalance if I move to the right */
double balance_val; /* how imbalanced is it */
double balance_best; /* best balance yet if trying hard */
bool flag; /* condition indicator */
int to = -1, from; /* sets moving into / out of */
int rtop, ltop; /* top of each set of buckets */
int * to_top; /* ptr to top of set moving to */
int lvtx, rvtx; /* next vertex to move left/right */
int lweight, rweight; /* weights of moving vertices */
int weightfrom = 0; /* weight moving out of a set */
int list_length; /* how long is list of vertices to bucketsort? */
bool balanced; /* is partition balanced? */
bool temp_balanced; /* is intermediate partition balanced? */
bool ever_balanced; /* has any partition been balanced? */
int bestvtx = -1; /* best vertex to move */
int bestval = -1; /* best change in value for a vtx move */
int vweight; /* weight of best vertex */
int gtotal; /* sum of changes from moving */
int improved; /* total improvement from KL */
double bestg; /* maximum gtotal found in KL loop */
double bestg_min; /* smaller than any possible bestg */
int beststep; /* step where maximum value occurred */
int bestlength; /* step where maximum value occurred */
int neighbor; /* neighbor of a vertex */
int step_cutoff; /* number of negative steps in a row allowed */
int cost_cutoff; /* amount of negative d-values allowed */
int neg_steps; /* number of negative steps in a row */
int neg_cost; /* decrease in sum of d-values */
int vtx; /* vertex number */
int dval; /* dval of a vertex */
int group, group2; /* set that a vertex is assigned to */
bool left_too_big; /* is left set too large? */
bool right_too_big; /* is right set too large? */
int vwgt; /* weight of a vertex */
int gain; /* reduction in separator due to a move */
int neighbor2; /* neighbor of a vertex */
int step; /* loops through movements of vertices */
bool parity; /* sort forwards or backwards? */
bool done; /* has termination criteria been achieved? */
int nbad; /* number of unhelpful passes in a row */
int npass; /* total number of passes */
int nbadtries; /* number of unhelpful passes before quitting */
bool enforce_balance; /* force a balanced partition? */
bool enforce_balance_hard; /* really force a balanced partition? */
int i, j, k; /* loop counters */
nbadtries = KL_NTRIES_BAD;
enforce_balance = false;
enforce_balance_hard = false;
total_weight = goal[0] + goal[1];
bspace = (int *)Marshal.AllocHGlobal((nvtxs + 1) * sizeof(int));
if (bspace == null)
{
return(true);
}
bdy_ptr = *bndy_list;
list_length = 0;
while (*bdy_ptr != 0)
{
bspace[list_length++] = *bdy_ptr++;
}
Marshal.FreeHGlobal((IntPtr)(*bndy_list));
clear_dvals(graph, nvtxs, ldvals, rdvals, bspace, list_length);
step_cutoff = KL_BAD_MOVES;
cost_cutoff = maxdval * step_cutoff / 7;
if (cost_cutoff < step_cutoff)
{
cost_cutoff = step_cutoff;
}
partial_weight = weightsum[0] + weightsum[1];
ratio = partial_weight / total_weight;
delta0 = Math.Abs(weightsum[0] - goal[0] * ratio);
delta1 = Math.Abs(weightsum[1] - goal[1] * ratio);
balanced =
(delta0 + delta1 <= max_dev) && weightsum[0] != total_weight && weightsum[1] != total_weight;
bestg_min = -2.0 * nvtxs * maxdval;
parity = false;
nbad = 0;
npass = 0;
improved = 0;
done = false;
while (!done)
{
npass++;
ever_balanced = false;
balance_best = delta0 + delta1;
/* Initialize various quantities. */
ltop = rtop = 2 * maxdval;
gtotal = 0;
bestg = bestg_min;
beststep = -1;
bestlength = list_length;
out_list = null;
neg_steps = 0;
/* Compute the initial d-values, and bucket-sort them. */
time = seconds();
bucketsortsv(graph, nvtxs, lbuckets, rbuckets, llistspace, rlistspace, ldvals, rdvals, sets,
maxdval, parity, bspace, list_length);
parity = !parity;
kl_bucket_time += seconds() - time;
if (DEBUG_KL == DebugFlagKL.PrintBucket)
{
Console.WriteLine("After sorting, left buckets:");
p1bucket(lbuckets, llistspace, maxdval);
Console.WriteLine(" right buckets:");
p1bucket(rbuckets, rlistspace, maxdval);
}
/* Now determine the set of vertex moves. */
for (step = 1;; step++)
{
/* Find the highest d-value in each set. */
/* But only consider moves from large to small sets, or moves */
/* in which balance is preserved. */
/* Break ties in some nonarbitrary manner. */
bestval = -maxdval - 1;
partial_weight = weightsum[0] + weightsum[1];
ratio = partial_weight / total_weight;
left_too_big = (weightsum[0] > (goal[0] + .5 * max_dev) * ratio);
right_too_big = (weightsum[1] > (goal[1] + .5 * max_dev) * ratio);
while (ltop >= 0 && lbuckets[ltop] == null)
{
--ltop;
}
if (ltop >= 0 && !left_too_big)
{
lvtx = (int)(((long)lbuckets[ltop] - (long)llistspace) / sizeof(bilist));
lweight = graph[lvtx]->vwgt;
rweight = lweight - (ltop - maxdval);
weightfrom = rweight;
to = 0;
bestvtx = lvtx;
bestval = ltop - maxdval;
partial_weight = weightsum[0] + lweight + weightsum[1] - rweight;
ratio = partial_weight / total_weight;
left_imbalance = Math.Max(Math.Abs(weightsum[0] + lweight - goal[0] * ratio),
Math.Abs(weightsum[1] - rweight - goal[1] * ratio));
}
while (rtop >= 0 && rbuckets[rtop] == null)
{
--rtop;
}
if (rtop >= 0 && !right_too_big)
{
rvtx = (int)(((long)rbuckets[rtop] - (long)rlistspace) / sizeof(bilist));
rweight = graph[rvtx]->vwgt;
lweight = rweight - (rtop - maxdval);
partial_weight = weightsum[0] - lweight + weightsum[1] + rweight;
ratio = partial_weight / total_weight;
right_imbalance = Math.Max(Math.Abs(weightsum[0] - lweight - goal[0] * ratio),
Math.Abs(weightsum[1] + rweight - goal[1] * ratio));
if (rtop - maxdval > bestval || (rtop - maxdval == bestval &&
(right_imbalance < left_imbalance ||
(right_imbalance == left_imbalance && drandom() < .5))))
{
to = 1;
weightfrom = lweight;
bestvtx = rvtx;
bestval = rtop - maxdval;
}
}
if (bestval == -maxdval - 1)
{
/* No allowed moves */
if (DEBUG_KL != DebugFlagKL.NoDebugging)
{
Console.WriteLine("No KLV moves at step {0:d}. bestg = {1:g} at step {2:d}.", step, bestg, beststep);
}
break;
}
if (to == 0)
{
from = 1;
to_listspace = llistspace;
from_listspace = rlistspace;
to_dvals = ldvals;
from_dvals = rdvals;
to_buckets = lbuckets;
from_buckets = rbuckets;
to_top = <op;
}
else
{
from = 0;
to_listspace = rlistspace;
from_listspace = llistspace;
to_dvals = rdvals;
from_dvals = ldvals;
to_buckets = rbuckets;
from_buckets = lbuckets;
to_top = &rtop;
}
vweight = graph[bestvtx]->vwgt;
weightsum[to] += vweight;
weightsum[from] -= weightfrom;
/* Check if this partition is balanced. */
partial_weight = weightsum[0] + weightsum[1];
ratio = partial_weight / total_weight;
delta0 = Math.Abs(weightsum[0] - goal[0] * ratio);
delta1 = Math.Abs(weightsum[1] - goal[1] * ratio);
temp_balanced = (delta0 + delta1 <= max_dev) && weightsum[0] != total_weight &&
weightsum[1] != total_weight;
ever_balanced = (ever_balanced || temp_balanced);
balance_val = delta0 + delta1;
gtotal += bestval;
if ((gtotal > bestg && temp_balanced) ||
(enforce_balance_hard && balance_val < balance_best))
{
bestg = gtotal;
beststep = step;
if (balance_val < balance_best)
{
balance_best = balance_val;
}
if (temp_balanced)
{
enforce_balance_hard = false;
}
}
if (DEBUG_KL == DebugFlagKL.MoreInfo || DEBUG_KL == DebugFlagKL.PrintBucket)
{
Console.WriteLine("At KLV step {0:d}, bestvtx={1:d}, bestval={2:d} (2->{3:d}), wt0 = {4:g,} wt1 = {5:g}", step, bestvtx, bestval, to, weightsum[0], weightsum[1]);
}
/* Monitor the stopping criteria. */
if (bestval < 0)
{
if (!enforce_balance || ever_balanced)
{
neg_steps++;
}
if (bestg != bestg_min)
{
neg_cost = (int)bestg - gtotal;
}
else
{
neg_cost = -maxdval - 1;
}
if ((neg_steps > step_cutoff || neg_cost > cost_cutoff) &&
!(enforce_balance && bestg == bestg_min))
{
if (DEBUG_KL != DebugFlagKL.NoDebugging)
{
if (neg_steps > step_cutoff || neg_cost > cost_cutoff)
{
Console.WriteLine("KLV step cutoff at step {0:d}. bestg = {1:g} at step {2:d}.", step, bestg, beststep);
}
}
weightsum[to] -= vweight;
weightsum[from] += weightfrom;
break;
}
}
else if (bestval > 0)
{
neg_steps = 0;
}
/* Remove vertex from its buckets, and flag it as finished. */
sets[bestvtx] = to;
removebilist(&to_listspace[bestvtx], &to_buckets[bestval + maxdval]);
/*
* printf("After to removebilist\n");
* p1bucket(to_buckets, to_listspace, maxdval);
*/
if (from_dvals[bestvtx] != -maxdval - 1)
{
removebilist(&from_listspace[bestvtx], &from_buckets[from_dvals[bestvtx] + maxdval]);
/*
* printf("After from removebilist\n");
* p1bucket(from_buckets, from_listspace, maxdval);
*/
}
from_dvals[bestvtx] = -maxdval - 1;
/* Now keep track of vertices moved out of separator so */
/* I can restore them as needed. */
llistspace[bestvtx].next = out_list;
out_list = &(llistspace[bestvtx]);
/* Now update the d-values of all the neighbors */
/* And neighbors of neighbors ... */
/* If left move:
* 1. Separator neighbors right gain => infinity
* 2. Left neighbors unaffected.
* 3. Right neighbors move into separator.
* A. Right gain = infinity.
* B. Left gain = computed.
* C. For any of their neighbors in separator increase left gain.
*/
edges = graph[bestvtx]->edges;
for (j = graph[bestvtx]->nedges - 1; j != 0; j--)
{
neighbor = *(++edges);
group = sets[neighbor];
if (group == 2)
{
/* In separator. */
gain = from_dvals[neighbor] + maxdval;
/* Gain in the from direction => -infinity */
if (gain >= 0)
{
removebilist(&from_listspace[neighbor], &from_buckets[gain]);
/*
* printf("\n After removing %d\n", neighbor);
* p1bucket(from_buckets, from_listspace, maxdval);
*/
from_dvals[neighbor] = -maxdval - 1;
}
}
else if (group == from)
{
/* Gain in the from direction => -infinity */
sets[neighbor] = 2;
from_dvals[neighbor] = -maxdval - 1;
if (to == 0)
{
bspace[list_length++] = -neighbor;
}
else
{
bspace[list_length++] = neighbor;
}
edges2 = graph[neighbor]->edges;
vwgt = graph[neighbor]->vwgt;
gain = graph[neighbor]->vwgt;
flag = false;
for (k = graph[neighbor]->nedges - 1; k != 0; k--)
{
neighbor2 = *(++edges2);
group2 = sets[neighbor2];
if (group2 == 2)
{
dval = to_dvals[neighbor2] + maxdval;
if (dval >= 0)
{
movebilist(&to_listspace[neighbor2], &to_buckets[dval], &to_buckets[dval + vwgt]);
/*
* printf("\n After moving %d from bucket %d to bucket
* %d\n", neighbor2, dval, dval + vwgt);
* p1bucket(to_buckets, to_listspace, maxdval);
*/
to_dvals[neighbor2] += vwgt;
dval += vwgt;
if (dval > *to_top)
{
*to_top = dval;
}
}
}
else if (group2 == from)
{
gain -= graph[neighbor2]->vwgt;
if (to_dvals[neighbor2] + maxdval < 0)
{
flag = true;
}
}
}
if (flag)
{
/* Not allowed to move further. */
to_dvals[neighbor] = -maxdval - 1;
}
else
{
to_dvals[neighbor] = gain;
/* place in appropriate bucket */
gain += maxdval;
add2bilist(&to_listspace[neighbor], &to_buckets[gain]);
/*
* printf("\nAfter adding %d to bucket %d\n", neighbor, gain -
* maxdval);
* p1bucket(to_buckets, to_listspace, maxdval);
*/
if (gain > *to_top)
{
*to_top = gain;
}
}
}
}
if (beststep == step)
{
bestlength = list_length;
}
if (DEBUG_KL == DebugFlagKL.PrintBucket)
{
Console.WriteLine("\n-- After step, left buckets:");
p1bucket(lbuckets, llistspace, maxdval);
Console.WriteLine(" right buckets:");
p1bucket(rbuckets, rlistspace, maxdval);
}
}
/* Done with a pass; should we actually perform any swaps? */
if (bestg > 0 || (bestg != bestg_min && !balanced && enforce_balance))
{
improved += (int)bestg;
}
else
{
if (enforce_balance_hard)
{
/* I've done the best I can, give up. */
done = true;
}
if (enforce_balance)
{
enforce_balance_hard = true;
}
enforce_balance = true;
nbad++;
}
/* Work backwards, undoing all the undesirable moves. */
/* First reset vertices moved out of the separator. */
if (out_list != null)
{
if (beststep < 0)
{
beststep = 0;
}
for (i = step - 1; i > beststep; i--)
{
vtx = (int)(((long)out_list - (long)llistspace) / sizeof(bilist));
if (sets[vtx] != 2)
{
weightsum[sets[vtx]] -= graph[vtx]->vwgt;
}
sets[vtx] = 2;
out_list = out_list->next;
}
}
for (i = list_length - 1; i >= bestlength; i--)
{
vtx = bspace[i];
if (vtx < 0)
{
if (sets[-vtx] == 2)
{
weightsum[1] += graph[-vtx]->vwgt;
}
sets[-vtx] = 1;
}
else
{
if (sets[vtx] == 2)
{
weightsum[0] += graph[vtx]->vwgt;
}
sets[vtx] = 0;
}
}
partial_weight = weightsum[0] + weightsum[1];
ratio = partial_weight / total_weight;
delta0 = Math.Abs(weightsum[0] - goal[0] * ratio);
delta1 = Math.Abs(weightsum[1] - goal[1] * ratio);
balanced = (delta0 + delta1 <= max_dev) && weightsum[0] != total_weight &&
weightsum[1] != total_weight;
done = done || (nbad >= nbadtries && balanced);
if (KL_MAX_PASS > 0)
{
done = done || (npass == KL_MAX_PASS && balanced);
}
if (!done)
{
/* Rezero dval values. */
clear_dvals(graph, nvtxs, ldvals, rdvals, bspace, list_length);
}
/* Construct list of separator vertices to pass to buckets or return */
list_length = make_sep_list(bspace, list_length, sets);
if (done)
{
bspace[list_length] = 0;
bspace = (int *)Marshal.ReAllocHGlobal((IntPtr)bspace, new IntPtr((list_length + 1) * sizeof(int)));
*bndy_list = bspace;
}
gain = 0;
j = k = 0;
for (i = 1; i <= nvtxs; i++)
{
if (sets[i] == 0)
{
j += graph[i]->vwgt;
}
else if (sets[i] == 1)
{
k += graph[i]->vwgt;
}
else if (sets[i] == 2)
{
gain += graph[i]->vwgt;
}
}
/*
* printf("\nAfter pass of KLV: sets = %d/%d, sep = %d (bestg = %g)\n\n\n", j, k, gain, bestg);
*/
}
if (DEBUG_KL != DebugFlagKL.NoDebugging)
{
Console.WriteLine(" KLV required {0:d} passes to improve by {1:d}.", npass, improved);
}
return(false);
}
private static int make_kl_list(vtx_data **graph, /* data structure for graph */
bilist *movelist, /* list of vtxs to be moved */
bilist ****buckets, /* array of lists for bucket sort */
bilist **listspace, /* list data structure for each vertex */
int *sets, /* processor each vertex is assigned to */
int nsets, /* number of sets divided into */
int *bspace, /* list of active vertices for bucketsort */
int **dvals, /* d-values for each transition */
int maxdval /* maximum d-value for a vertex */
)
{
bilist **list; /* bucket to erase element from */
bilist * vptr; /* loops through movelist */
int * bptr; /* loops through bspace */
int * iptr; /* loops through edge list */
int vtx; /* vertex that was moved */
int neighbor; /* neighbor of a vertex */
int myset; /* set a vertex is in */
int newset; /* loops through other sets */
int list_length; /* number of values put in bspace */
int size; /* array spacing */
int i, l; /* loop counter */
/* First push all the moved vertices onto list, so they can be flagged. */
/* They've already been removed from buckets, so want to avoid them. */
size = (int)(&(listspace[0][1]) - &(listspace[0][0]));
vptr = movelist;
bptr = bspace;
list_length = 0;
while (vptr != null)
{
vtx = ((int)(vptr - listspace[0])) / size;
*bptr++ = vtx;
if (sets[vtx] >= 0)
{
sets[vtx] = -sets[vtx] - 1;
}
++list_length;
vptr = vptr->next;
}
/* Now look at all the neighbors of moved vertices. */
vptr = movelist;
while (vptr != null)
{
vtx = ((int)(vptr - listspace[0])) / size;
iptr = graph[vtx]->edges;
for (i = graph[vtx]->nedges - 1; i != 0; i--)
{
neighbor = *(++iptr);
if (sets[neighbor] >= 0)
{
*bptr++ = neighbor;
++list_length;
myset = sets[neighbor];
sets[neighbor] = -sets[neighbor] - 1;
/* Remove neighbor entry from all his buckets. */
/* Note: vertices in movelist already removed from buckets. */
l = 0;
for (newset = 0; newset < nsets; newset++)
{
if (newset != myset)
{
list = &buckets[myset][newset][dvals[neighbor][l] + maxdval];
removebilist(&listspace[l][neighbor], list);
l++;
}
}
}
}
vptr = vptr->next;
}
/* Now that list is constructed, go reconstruct all the set numbers. */
bptr = bspace;
for (i = list_length; i != 0; i--)
{
vtx = *bptr++;
sets[vtx] = -sets[vtx] - 1;
}
return(list_length);
}
/* Idea:
* 'buckets[i][j]' is a set of buckets to sort moves from i to j.
* listspace[i] is space for lists in buckets[i][j].
* Loop through all nonequal pairs [i][j], taking the first element
* in each list. Compare them all to find the largest allowed move.
* Make that move, and save it in movelist.
*/
public static bool nway_kl(vtx_data **graph, /* data structure for graph */
int nvtxs, /* number of vtxs in graph */
bilist ****buckets, /* array of lists for bucket sort */
bilist **listspace, /* list data structure for each vertex */
int **tops, /* 2-D array of top of each set of buckets */
int **dvals, /* d-values for each transition */
int *sets, /* processor each vertex is assigned to */
int maxdval, /* maximum d-value for a vertex */
int nsets, /* number of sets divided into */
double [] goal, /* desired set sizes */
float *[] term_wgts, /* weights for terminal propagation */
int [][] hops, /* cost of set transitions */
int max_dev, /* largest allowed deviation from balance */
bool useEdgeWeights, /* are edge weights being used? */
int **bndy_list, /* list of vertices on boundary (0 ends) */
double [] startweight /* sum of vweights in each set (in and out) */
)
/* Suaris and Kedem algorithm for quadrisection, generalized to an */
/* arbitrary number of sets, with intra-set cost function specified by hops. */
/* Note: this is for a single divide step. */
/* Also, sets contains an initial (possibly crummy) partitioning. */
{
bilist * movelist; /* list of vtxs to be moved */
bilist **endlist; /* end of movelists */
bilist * bestptr; /* best vertex in linked list */
bilist * bptr; /* loops through bucket list */
float * ewptr = null; /* loops through edge weights */
double * locked = null; /* weight of vertices locked in a set */
double * loose = null; /* weight of vtxs that can move from a set */
int * bspace = null; /* list of active vertices for bucketsort */
double * weightsum = null; /* sum of vweights for each partition */
int * edges = null; /* edge list for a vertex */
int * bdy_ptr = null; /* loops through bndy_list */
double time; /* timing parameter */
double delta; /* desire of sets to change size */
double bestdelta = -1; /* strongest delta value */
double deltaplus; /* largest negative deviation from goal size */
double deltaminus; /* largest negative deviation from goal size */
int list_length; /* how long is list of vertices to bucketsort? */
bool balanced; /* is partition balanced? */
bool temp_balanced; /* is intermediate partition balanced? */
bool ever_balanced; /* has any partition been balanced? */
int bestvtx = -1; /* best vertex to move */
int bestval = -1; /* best change in value for a vtx move */
int bestfrom = -1, bestto = -1; /* sets best vertex moves between */
int vweight; /* weight of best vertex */
int gtotal; /* sum of changes from moving */
int improved; /* total improvement from KL */
double balance_val = 0.0; /* how imbalanced is it */
double balance_best; /* best balance yet if trying hard */
double bestg; /* maximum gtotal found in KL loop */
double bestg_min; /* smaller than any possible bestg */
int beststep; /* step where maximum value occurred */
int neighbor; /* neighbor of a vertex */
int step_cutoff; /* number of negative steps in a row allowed */
int cost_cutoff; /* amount of negative d-values allowed */
int neg_steps; /* number of negative steps in a row */
int neg_cost; /* decrease in sum of d-values */
int vtx; /* vertex number */
int dval; /* dval of a vertex */
int group; /* set that a vertex is assigned to */
double cut_cost; /* if term_prop; relative cut/hop importance */
int diff; /* change in a d-value */
int stuck1st, stuck2nd; /* how soon will moves be disallowed? */
int beststuck1 = -1, beststuck2 = -1; /* best stuck values for tie-breaking */
int eweight; /* a particular edge weight */
bool worth_undoing; /* is it worth undoing list? */
float undo_frac; /* fraction of vtxs indicating worth of undoing */
int step; /* loops through movements of vertices */
bool parity; /* sort forwards or backwards? */
bool done; /* has termination criteria been achieved? */
int nbad; /* number of unhelpful passes in a row */
int npass; /* total number of passes */
int nbadtries; /* number of unhelpful passes before quitting */
bool enforce_balance; /* force a balanced partition? */
bool enforce_balance_hard; /* really force a balanced partition? */
bool balance_trouble; /* even balance_hard isn't working */
int size; /* array spacing */
int i, j, k, l; /* loop counters */
nbadtries = KL_NTRIES_BAD;
enforce_balance = false;
temp_balanced = false;
enforce_balance_hard = false;
balance_trouble = false;
size = (int)(&(listspace[0][1]) - &(listspace[0][0]));
undo_frac = 0.3f;
cut_cost = 1;
if (term_wgts[1] != null)
{
if (CUT_TO_HOP_COST > 1)
{
cut_cost = CUT_TO_HOP_COST;
}
}
bspace = (int *)Marshal.AllocHGlobal(nvtxs * sizeof(int));
weightsum = (double *)Marshal.AllocHGlobal(nsets * sizeof(double));
locked = (double *)Marshal.AllocHGlobal(nsets * sizeof(double));
loose = (double *)Marshal.AllocHGlobal(nsets * sizeof(double));
if (bspace == null || weightsum == null || locked == null || loose == null)
{
Marshal.FreeHGlobal((IntPtr)loose);
Marshal.FreeHGlobal((IntPtr)locked);
Marshal.FreeHGlobal((IntPtr)weightsum);
Marshal.FreeHGlobal((IntPtr)bspace);
return(true);
}
if (*bndy_list != null)
{
bdy_ptr = *bndy_list;
list_length = 0;
while (*bdy_ptr != 0)
{
bspace[list_length++] = *bdy_ptr++;
}
Marshal.FreeHGlobal((IntPtr)(*bndy_list));
if (list_length == 0) /* No boundary -> make everybody bndy. */
{
for (i = 0; i < nvtxs; i++)
{
bspace[i] = i + 1;
}
list_length = nvtxs;
}
/* Set dvals to flag uninitialized vertices. */
for (i = 1; i <= nvtxs; i++)
{
dvals[i][0] = 3 * maxdval;
}
}
else
{
list_length = nvtxs;
}
step_cutoff = KL_BAD_MOVES;
cost_cutoff = maxdval * step_cutoff / 7;
if (cost_cutoff < step_cutoff)
{
cost_cutoff = step_cutoff;
}
deltaminus = deltaplus = 0;
for (i = 0; i < nsets; i++)
{
if (startweight[i] - goal[i] > deltaplus)
{
deltaplus = startweight[i] - goal[i];
}
else if (goal[i] - startweight[i] > deltaminus)
{
deltaminus = goal[i] - startweight[i];
}
}
balanced = (deltaplus + deltaminus <= max_dev);
bestg_min = -2.0 * nvtxs * maxdval;
parity = false;
eweight = (int)(cut_cost + .5);
nbad = 0;
npass = 0;
improved = 0;
done = false;
while (!done)
{
npass++;
ever_balanced = false;
/* Initialize various quantities. */
balance_best = 0;
for (i = 0; i < nsets; i++)
{
for (j = 0; j < nsets; j++)
{
tops[i][j] = 2 * maxdval;
}
weightsum[i] = startweight[i];
loose[i] = weightsum[i];
locked[i] = 0;
balance_best += goal[i];
}
gtotal = 0;
bestg = bestg_min;
beststep = -1;
movelist = null;
endlist = &movelist;
neg_steps = 0;
/* Compute the initial d-values, and bucket-sort them. */
time = seconds();
if (nsets == 2)
{
bucketsorts_bi(graph, nvtxs, buckets, listspace, dvals, sets, term_wgts, maxdval, nsets,
parity, hops, bspace, list_length, npass, useEdgeWeights);
}
else
{
bucketsorts(graph, nvtxs, buckets, listspace, dvals, sets, term_wgts, maxdval, nsets, parity,
hops, bspace, list_length, npass, useEdgeWeights);
}
parity = !parity;
kl_bucket_time += seconds() - time;
if (DEBUG_KL == DebugFlagKL.PrintBucket)
{
pbuckets(buckets, listspace, maxdval, nsets);
}
/* Now determine the set of K-L moves. */
for (step = 1;; step++)
{
/* Find the highest d-value in each set. */
/* But only consider moves from large to small sets, or moves */
/* in which balance is preserved. */
/* Break ties in some nonarbitrary manner. */
bestval = -maxdval - 1;
for (i = 0; i < nsets; i++)
{
for (j = 0; j < nsets; j++)
{
/* Only allow moves from large sets to small sets, or */
/* moves which preserve balance. */
if (i != j)
{
/* Find the best move from i to j. */
for (k = tops[i][j]; k >= 0 && buckets[i][j][k] == null; k--)
{
;
}
tops[i][j] = k;
if (k >= 0)
{
l = (j > i) ? j - 1 : j;
vtx = ((int)(buckets[i][j][k] - listspace[l])) / size;
vweight = graph[vtx]->vwgt;
if ((enforce_balance_hard && weightsum[i] >= goal[i] && weightsum[j] <= goal[j] &&
weightsum[i] - goal[i] - (weightsum[j] - goal[j]) > max_dev) ||
(!enforce_balance_hard && weightsum[i] >= goal[i] && weightsum[j] <= goal[j]) ||
(!enforce_balance_hard &&
weightsum[i] - vweight - goal[i] > -(double)((max_dev + 1) / 2) &&
weightsum[j] + vweight - goal[j] < (double)((max_dev + 1) / 2)))
{
/* Is it the best move seen so far? */
if (k - maxdval > bestval)
{
bestval = k - maxdval;
bestvtx = vtx;
bestto = j;
/* DO I NEED ALL THIS DATA? Just to break ties. */
bestdelta = Math.Abs(weightsum[i] - vweight - goal[i]) +
Math.Abs(weightsum[j] + vweight - goal[j]);
beststuck1 = (int)Math.Min(loose[i], goal[j] - locked[j]);
beststuck2 = (int)Math.Max(loose[i], goal[j] - locked[j]);
}
else if (k - maxdval == bestval)
{
/* Tied. Is better balanced than current best? */
/* If tied, move among sets with most freedom. */
stuck1st = (int)Math.Min(loose[i], goal[j] - locked[j]);
stuck2nd = (int)Math.Max(loose[i], goal[j] - locked[j]);
delta = Math.Abs(weightsum[i] - vweight - goal[i]) +
Math.Abs(weightsum[j] + vweight - goal[j]);
/* NOTE: Randomization in this check isn't ideal */
/* if more than two guys are tied. */
if (delta < bestdelta ||
(delta == bestdelta &&
(stuck1st > beststuck1 ||
(stuck1st == beststuck1 &&
(stuck2nd > beststuck2 ||
(stuck2nd == beststuck2 && (KL_RANDOM && drandom() < .5)))))))
{
bestval = k - maxdval;
bestvtx = vtx;
bestto = j;
bestdelta = delta;
beststuck1 = stuck1st;
beststuck2 = stuck2nd;
}
}
}
}
}
}
}
if (bestval == -maxdval - 1) /* No allowed moves */
{
if (DEBUG_KL != DebugFlagKL.NoDebugging)
{
Console.WriteLine("No KL moves at step {0:d}. bestg = {1:g} at step {2:d}.\n", step, bestg, beststep);
}
break;
}
bestptr = &(listspace[0][bestvtx]);
bestfrom = sets[bestvtx];
vweight = graph[bestvtx]->vwgt;
weightsum[bestto] += vweight;
weightsum[bestfrom] -= vweight;
loose[bestfrom] -= vweight;
locked[bestto] += vweight;
if (enforce_balance) /* Check if this partition is balanced. */
{
deltaminus = deltaplus = 0;
for (i = 0; i < nsets; i++)
{
if (weightsum[i] - goal[i] > deltaplus)
{
deltaplus = weightsum[i] - goal[i];
}
else if (goal[i] - weightsum[i] > deltaminus)
{
deltaminus = goal[i] - weightsum[i];
}
}
balance_val = deltaminus + deltaplus;
temp_balanced = (balance_val <= max_dev);
ever_balanced = (ever_balanced || temp_balanced);
}
gtotal += bestval;
if (((gtotal > bestg && (!enforce_balance || temp_balanced)) ||
(enforce_balance_hard && balance_val < balance_best)) &&
step != nvtxs)
{
bestg = gtotal;
beststep = step;
if (enforce_balance_hard)
{
balance_best = balance_val;
}
if (temp_balanced)
{
enforce_balance_hard = false;
}
}
if (DEBUG_KL == DebugFlagKL.MoreInfo || DEBUG_KL == DebugFlagKL.PrintBucket)
{
Console.WriteLine("At KL step {0:d}, bestvtx={1:d}, bestval={2:d} ({3:d}-> {4:d})", step, bestvtx, bestval, bestfrom, bestto);
}
/* Monitor the stopping criteria. */
if (bestval < 0)
{
if (!enforce_balance || ever_balanced)
{
neg_steps++;
}
if (bestg != bestg_min)
{
neg_cost = (int)(bestg - gtotal);
}
else
{
neg_cost = -maxdval - 1;
}
if ((neg_steps > step_cutoff || neg_cost > cost_cutoff) &&
!(enforce_balance && bestg == bestg_min) && (beststep != step))
{
if (DEBUG_KL != DebugFlagKL.NoDebugging)
{
if (neg_steps > step_cutoff)
{
Console.WriteLine("KL step cutoff at step {0:d}. bestg = {1:g} at step {2:d}.", step, bestg, beststep);
}
else if (neg_cost > cost_cutoff)
{
Console.WriteLine("KL cost cutoff at step {0:d}. bestg = {1:g} at step {2:d}.", step, bestg, beststep);
}
}
break;
}
}
else if (bestval > 0)
{
neg_steps = 0;
}
/* Remove vertex from its buckets, and flag it as finished. */
l = 0;
for (k = 0; k < nsets; k++)
{
if (k != bestfrom)
{
dval = dvals[bestvtx][l] + maxdval;
removebilist(&listspace[l][bestvtx], &buckets[bestfrom][k][dval]);
l++;
}
}
/* Is there a better way to do this? */
sets[bestvtx] = -sets[bestvtx] - 1;
/* Set up the linked list of moved vertices. */
bestptr->next = null;
bestptr->prev = (bilist *)(ulong)bestto;
*endlist = bestptr;
endlist = &(bestptr->next);
/* Now update the d-values of all the neighbors */
edges = graph[bestvtx]->edges;
if (useEdgeWeights)
{
ewptr = graph[bestvtx]->ewgts;
}
for (j = graph[bestvtx]->nedges - 1; j != 0; j--)
{
neighbor = *(++edges);
if (useEdgeWeights)
{
eweight = (int)(*(++ewptr) * cut_cost + .5);
}
/* First make sure neighbor is alive. */
if (sets[neighbor] >= 0)
{
group = sets[neighbor];
if (dvals[neighbor][0] >= 3 * maxdval)
{
/* New vertex, not yet in buckets. */
/* Can't be neighbor of moved vtx, so compute */
/* initial dvals and buckets, then update. */
bucketsort1(graph, neighbor, buckets, listspace, dvals, sets, term_wgts, maxdval, nsets,
hops, useEdgeWeights);
}
l = 0;
for (k = 0; k < nsets; k++)
{
if (k != group)
{
diff = eweight * (hops[k][bestfrom] - hops[group][bestfrom] + hops[group][bestto] -
hops[k][bestto]);
dval = dvals[neighbor][l] + maxdval;
movebilist(&listspace[l][neighbor], &buckets[group][k][dval],
&buckets[group][k][dval + diff]);
dvals[neighbor][l] += diff;
dval += diff;
if (dval > tops[group][k])
{
tops[group][k] = dval;
}
l++;
}
}
}
}
if (DEBUG_KL == DebugFlagKL.PrintBucket)
{
pbuckets(buckets, listspace, maxdval, nsets);
}
}
/* Done with a pass; should we actually perform any swaps? */
bptr = movelist;
if (bestg > 0 || (bestg != bestg_min && !balanced && enforce_balance) ||
(bestg != bestg_min && balance_trouble))
{
improved += (int)bestg;
for (i = 1; i <= beststep; i++)
{
vtx = ((int)(bptr - listspace[0])) / size;
bestto = (int)(ulong)bptr->prev;
startweight[bestto] += graph[vtx]->vwgt;
startweight[-sets[vtx] - 1] -= graph[vtx]->vwgt;
sets[vtx] = bestto;
bptr = bptr->next;
}
deltaminus = deltaplus = 0;
for (i = 0; i < nsets; i++)
{
if (startweight[i] - goal[i] > deltaplus)
{
deltaplus = startweight[i] - goal[i];
}
else if (goal[i] - startweight[i] > deltaminus)
{
deltaminus = goal[i] - startweight[i];
}
}
/*
* printf(" deltaplus = %f, deltaminus = %f, max_dev = %d\n", deltaplus, deltaminus, max_dev);
*/
balanced = (deltaplus + deltaminus <= max_dev);
}
else
{
nbad++;
}
if (!balanced || bptr == movelist)
{
if (enforce_balance)
{
if (enforce_balance_hard)
{
balance_trouble = true;
}
enforce_balance_hard = true;
}
enforce_balance = true;
nbad++;
}
worth_undoing = (step < undo_frac * nvtxs);
done = (nbad >= nbadtries && balanced);
if (KL_MAX_PASS > 0)
{
done = done || (npass == KL_MAX_PASS && balanced);
}
if (!done) /* Prepare for next pass. */
{
if (KL_UNDO_LIST && worth_undoing && !balance_trouble)
{
/* Make a list of modified vertices for next bucketsort. */
/* Also, ensure these vertices are removed from their buckets. */
list_length =
make_kl_list(graph, movelist, buckets, listspace, sets, nsets, bspace, dvals, maxdval);
}
}
if (done || !(KL_UNDO_LIST && worth_undoing && !balance_trouble))
{
/* Restore set numbers of remaining, altered vertices. */
while (bptr != null)
{
vtx = ((int)(bptr - listspace[0])) / size;
sets[vtx] = -sets[vtx] - 1;
bptr = bptr->next;
}
list_length = nvtxs;
}
if (done && *bndy_list != null)
{
make_bndy_list(graph, movelist, buckets, listspace, sets, nsets, bspace, tops, bndy_list);
}
}
if (DEBUG_KL != DebugFlagKL.NoDebugging)
{
Console.WriteLine(" KL required {0:d} passes to improve by {1:d}.", npass, improved);
}
Marshal.FreeHGlobal((IntPtr)loose);
Marshal.FreeHGlobal((IntPtr)locked);
Marshal.FreeHGlobal((IntPtr)weightsum);
Marshal.FreeHGlobal((IntPtr)bspace);
return(false);
}