public void Reverse(cTSP_LIST_NODE from, cTSP_LIST_NODE to)
{
cTSP_LIST_NODE l1, l2, l3, l4, l5, l6;
l1 = from;
l2 = to;
l3 = from.Next;
l4 = to.Prev;
while (((l3.Prev != l4) && (l4.Next != l3)) && (l1 != l2))
{
//assign
l1.Next = l4;
l2.Prev = l3;
l5 = l4.Prev;
l4.Prev = l1;
l6 = l3.Next;
l3.Next = l2;
//shift
l1 = l4;
l2 = l3;
l4 = l5;
l3 = l6;
}
}
bool std3opt()
{
//do
// {
ret = false;
float best = float.MaxValue;
cTSP_LIST_NODE b1 = null, b2 = null, b3 = null;
l1 = list_tour.First;
l1b = l1.Prev.Prev; //n-1
for (; !l1.Equals(l1b); l1 = l1.Next)
{
t.a = l1.Value;
t.b = l1.Next.Value;
l2b = list_tour.First.Prev; //n-1
l3b = list_tour.First;
for (l2 = l1.Next; !l2.Equals(l2b); l2 = l2.Next)
{
t.c = l2.Value;
t.d = l2.Next.Value;
if (t.d == t.a)
{
break;
}
for (l3 = l2.Next; !l3.Equals(l3b); l3 = l3.Next)
{
t.e = l3.Value;
t.f = l3.Next.Value;
if ((t.swap = Best3optSwap2(/*min+tsp.distance[t.e,t.f]*/)) > 0.0)
{
if (best > gain)
{
best = gain;
best_swap = t;
b1 = l1;
b2 = l2;
b3 = l3;
}
}
} //for
} //for
} //for
if (best < EPSILON)
{
ret = true;
swapcase2(best_swap, b1, b2, b3);
}
//} while (ret);
return(ret);
} //std3opt
public c3opt(cTSP _tsp, byte _algo, bool _show, int _nn, bool _fast)
{
tsp = _tsp;
n = tsp.GetN();
algo = _algo;
showprog = _show;
nn = _nn;
fast = _fast;
list_tour = new cTSP_LIST(_tsp);
l1 = list_tour.First;
}
private void BuildFromTour()
{
int i;
cTSP_LIST_NODE l;
l = list = first = new cTSP_LIST_NODE();
for (i = 0; i < tsp.GetN() - 1; i++, l = l.Next)
{
l.Value = tsp.GetTourNode(i);
l.Next = new cTSP_LIST_NODE();
l.Next.Prev = l;
}
l.Value = tsp.GetTourNode(i);
l.Next = first;
first.Prev = l;
last = l;
}
bool std3optCandidateSet()
{
ret = false;
l1 = list_tour.First;
l1b = l1.Prev;
for (; !l1.Equals(l1b); l1 = l1.Next)
{
t.a = l1.Value;
t.b = l1.Next.Value;
l2b = l1b.Prev.Prev;
for (i = 0; i < nn; i++)
{
l2 = list_tour.Find(tsp.GetNN_Node(l1.Value, i));
if (l2 == null)
{
throw new NotSupportedException("nodo non trovato");
}
if (l2.Equals(l1))
{
continue;
}
if ((l2.Equals(l1.Next)) || (l2.Next.Equals(l1)))
{
continue;
}
t.c = l2.Value;
t.d = l2.Next.Value;
//da mettere come opzione!!!
//Fast
if ((fast) && (tsp.distance[t.a, t.b] <= tsp.distance[t.b, t.c]))
{
continue;
}
l3 = l2.Next.Next;
min = tsp.distance[t.a, t.b] + tsp.distance[t.c, t.d];
for (; !l3.Equals(l1); l3 = l3.Next)
{
if ((l3.Equals(l1.Next)) ||
(l3.Equals(l2)) || (l3.Equals(l2.Next)) ||
(l3.Next.Equals(l2)))
{
continue;
}
t.e = l3.Value;
t.f = l3.Next.Value;
if ((t.swap = Best3optSwap()) > 0)
{
ret = true;
swapcase1();
if ((t.swap != 5) && (i != 9))
{
i = 0;
}
min = tsp.distance[t.a, t.b] + tsp.distance[t.c, t.d];
}
} //for
} //for
} //for
return(ret);
}
private void swapcase2(TSWAP t, cTSP_LIST_NODE l1, cTSP_LIST_NODE l2, cTSP_LIST_NODE l3)
{
int etmp;
cTSP_LIST_NODE b, d, f, a, c, e;
a = l1;
c = l2;
e = l3;
b = a.Next;
d = c.Next;
f = e.Next;
switch (t.swap)
{
case 1: //t2
list_tour.Reverse(a, d);
t.b = t.c;
t.c = b.Value;
list_tour.Reverse(d.Prev, f);
t.d = t.e;
break;
case 2: //t3
list_tour.Reverse(a, d);
a.Next = d; d.Prev = a;
e.Next = c; c.Prev = e;
b.Next = f; f.Prev = b;
t.b = t.d;
t.d = t.c;
t.c = t.e;
break;
case 3: // t4
list_tour.Reverse(c, f);
a.Next = e; e.Prev = a;
d.Next = b; b.Prev = d;
c.Next = f; f.Prev = c;
etmp = t.b;
t.b = t.e;
t.c = t.d;
t.d = etmp;
break;
case 4: // t5
a.Next = d; d.Prev = a;
e.Next = b; b.Prev = e;
c.Next = f; f.Prev = c;
etmp = t.b;
t.b = t.d;
t.d = etmp;
t.c = t.e;
break;
case 5: //t6
list_tour.Reverse(c, f);
c.Next = e; e.Prev = c;
d.Next = f; f.Prev = d;
t.d = t.e;
break;
case 6: //t7
list_tour.Reverse(a, f);
etmp = t.c;
t.c = t.d;
t.d = etmp;
t.b = t.e;
break;
case 7: //t8
list_tour.Reverse(a, d);
a.Next = c; c.Prev = a;
b.Next = d; d.Prev = b;
etmp = t.b;
t.b = t.c;
t.c = etmp;
break;
}
}