private void RunSearch(int n, IMeasure measure)
{
var rnd = new Random();
while (!timeout)
{
// Generate random path
//var p = new[] {1, 3, 2, 0};
var p = Permutations.GetRandomPermutation(n);
var path = new UniversalNode[n];
for (int i = 0; i < n - 1; i++)
{
path[p[i]].Right = p[i + 1];
}
for (int i = 1; i < n; i++)
{
path[p[i]].Left = p[i - 1];
}
path[p[0]].Left = p[n - 1];
path[p[n - 1]].Right = p[0];
/*var pst = 0;
var st = path[0].Left;*/
int q = totalCount > 0 ? 1 : 0;
while (true)
{
// init
var i = rnd.Next(n);
var inext = path[i].Left;
var ipr = path[i].Next(inext);
int jpr = 0;
int j = 0;
int jnext = 0;
int kpr = 0;
int k = 0;
int knext = 0;
int trType = -1;
var found = false;
for (int icount = 0; icount < n; icount++)
{
// iterate
ipr = i;
i = inext;
inext = path[i].Next(ipr);
if (q == 1 && S[i, inext])
{
continue;
}
// init
j = inext;
jnext = i;
jpr = path[j].Next(jnext);
for (int jcount = 0; jcount < n - 3; jcount++)
{
// iterate
jpr = j;
j = jnext;
jnext = path[j].Next(jpr);
cycle++;
if (cycle >= ThreadCount * 10000)
{
lock (_lockStopwatch)
{
stopwatch.Stop();
if (stopwatch.ElapsedMilliseconds > timelimit)
{
timeout = true;
break;
}
cycle = 0;
stopwatch.Start();
}
}
/*// run 2-opt
if (inext != j && jnext != i)
{
if (measure[i, inext] + measure[j, jnext] > measure[i, j] + measure[inext, jnext])
{
found = true;
break;
}
}*/
// run 3-opt
// init
kpr = jpr;
k = j;
knext = jnext;
for (int kcount = 0; kcount < n - 3 - jcount; kcount++)
{
// iterate
kpr = k;
k = knext;
knext = path[k].Next(kpr);
double d;
if (measure[inext, k] + measure[i, jnext] <= measure[inext, jnext] + measure[i, k])
{
d = measure[inext, k] + measure[i, jnext];
trType = 0;
}
else
{
d = measure[inext, jnext] + measure[i, k];
trType = 1;
}
if (d + measure[j, knext] < measure[i, inext] + measure[j, jnext] + measure[k, knext])
{
found = true;
break;
}
// TODO: need more condition?
/*if (inext != j && jnext != k && knext != i)
{
if (measure[i, inext] + measure[j, jnext] + measure[k, knext]
> measure[i, jnext] + measure[j, knext] + measure[k, inext])
{
trType = 0;
found = true;
break;
}
if (measure[i, inext] + measure[j, jnext] + measure[k, knext]
> measure[i, jnext] + measure[j, k] + measure[inext, knext])
{
trType = 1;
found = true;
break;
}
}*/
}
/*if (found)
{
break;
}
k = -1;*/
if (timeout || found)
{
break;
}
/*if (i == st)
{
break;
}*/
}
if (timeout || found)
{
break;
}
}
if (!found)
{
if (q == 1)
{
q = 0;
continue;
}
break;
}
//var inext2 = path[inext].Next(i);
//var jprev = path[j].Next(jnext);
if (k < 0)
{
path[i].Change(inext, j);
path[j].Change(jnext, i);
path[inext].Change(i, jnext);
path[jnext].Change(j, inext);
}
else
{
if (trType == 0)
{
path[i].Change(inext, jnext);
path[j].Change(jnext, knext);
path[k].Change(knext, inext);
path[inext].Change(i, k);
path[jnext].Change(j, i);
path[knext].Change(k, j);
}
else
{
path[i].Change(inext, k);
path[j].Change(jnext, knext);
path[k].Change(knext, i);
path[inext].Change(i, jnext);
path[jnext].Change(j, inext);
path[knext].Change(k, j);
}
}
// heuristic shift
/*var sttmp = st;
st = path[st].Next(pst);
pst = sttmp;*/
}
var tpr = 0;
var t = path[0].Right;
p[0] = 0;
var count = 1;
while (t != 0)
{
p[count] = t;
count++;
var tmp = t;
t = path[t].Next(tpr);
tpr = tmp;
}
S[p[0], p[n - 1]] = true;
S[p[n - 1], p[0]] = true;
for (int i = 0; i < n - 1; i++)
{
S[p[i], p[i + 1]] = true;
S[p[i + 1], p[i]] = true;
}
var l = CalcLength(p, measure);
lock (_lockUpdateBest)
{
if (l < bestLength)
{
bestLength = l;
bestPath = p;
}
}
lock (_lockTotalCount)
{
totalCount++;
}
}
}
public override int[] GetPath(int n, IMeasure measure)
{
var stopwatch = Stopwatch.StartNew();
var cycle = 0;
var timelimit = RunProperties.RunTimeInSeconds;
var timeout = false;
int[] bestPath = null;
var bestLength = 1e30;
while (!timeout)
{
// Generate random path
//var p = new[] {1, 3, 2, 0};
var p = Permutations.GetRandomPermutation(n);
var path = new UniversalNode[n];
for (int i = 0; i < n - 1; i++)
{
path[p[i]].Right = p[i + 1];
}
for (int i = 1; i < n; i++)
{
path[p[i]].Left = p[i - 1];
}
path[p[0]].Left = p[n - 1];
path[p[n - 1]].Right = p[0];
var pst = 0;
var st = path[0].Left;
while (true)
{
var found = false;
var i = st;
var inext = path[i].Right;
var ipr = path[i].Next(inext);
int jpr = 0;
int j = 0;
int jnext = 0;
while (true)
{
cycle++;
if (cycle == 10000)
{
stopwatch.Stop();
if (stopwatch.ElapsedMilliseconds > timelimit * 1000)
{
timeout = true;
break;
}
cycle = 0;
stopwatch.Start();
}
jpr = i;
j = path[i].Next(ipr);
jnext = path[j].Next(jpr);
while (j != i)
{
if (inext != j && jnext != i)
{
if (measure[i, inext] + measure[j, jnext] > measure[i, j] + measure[inext, jnext])
{
found = true;
break;
}
}
jpr = j;
j = jnext;
jnext = path[j].Next(jpr);
}
if (found)
{
break;
}
ipr = i;
i = inext;
inext = path[i].Next(ipr);
if (i == st)
{
break;
}
}
if (!found)
{
break;
}
//var inext2 = path[inext].Next(i);
//var jprev = path[j].Next(jnext);
path[i].Change(inext, j);
path[j].Change(jnext, i);
path[inext].Change(i, jnext);
path[jnext].Change(j, inext);
var sttmp = st;
st = path[st].Next(pst);
pst = sttmp;
}
var tpr = 0;
var t = path[0].Right;
p[0] = 0;
var count = 1;
while (t != 0)
{
p[count] = t;
count++;
var tmp = t;
t = path[t].Next(tpr);
tpr = tmp;
}
var l = CalcLength(p, measure);
if (l < bestLength)
{
bestLength = l;
bestPath = p;
}
}
return bestPath;
}