EgtNumKernel 1.6l4 :

- aggiunta gestione ShortestPath.
2015-12-28 10:33:46 +00:00
parent d1dbe04a57
commit b71ff8c113
13 changed files with 1455 additions and 6 deletions
@@ -0,0 +1,80 @@
+//----------------------------------------------------------------------------
+//  EgalTech 2015-2015
+//----------------------------------------------------------------------------
+// File : TwoOpt.cpp        Data : 22.12.15        Versione : 1.6l4
+// Contenuto : Miglioramento del percorso spezzandolo in 2 parti e 
+//             ricollegando con una delle due parti invertite.
+//
+//                 K  Last              K  Last
+//                 o  o--<-             o--o--<-
+//                 |\/                  |
+//                 |/\                  |
+//                 o  o--->             o--o--->
+//             First  K+1           First  K+1
+//
+// Modifiche : 22.12.15 DS Creazione modulo.
+//
+//
+//----------------------------------------------------------------------------
+
+//--------------------------- Include ----------------------------------------
+#include "stdafx.h"
+#include "ShortestPath.h"
+
+// ----------------------------------------------------------------------------
+unsigned
+ShortestPath::TwoOpt( NODE* pPath)
+{
+   const int MAX_TRY = 2048 ;
+   unsigned nTry = 1 ;
+   unsigned nCount = 1 ;
+   NODE* pFirst = pPath ;
+   do {
+      NODE* pLast = pFirst->pPrev ;
+      NODE* pKth = pFirst->pNext ;
+      do {
+        // lunghezza originale dei tratti da scambiare
+         unsigned nEXIST = ArcCost( pLast->nPos, pFirst->nPos) +
+                           ArcCost( pKth->nPos, pKth->pNext->nPos) ;
+        // nuova lunghezza dei tratti da scambiare
+         unsigned nTEST = ArcCost( pFirst->nPos, pKth->pNext->nPos) +
+                          ArcCost( pLast->nPos, pKth->nPos) ;
+        // lunghezze originali e nuova del tratto intermedio che viene invertito
+         for ( NODE* pCurr = pFirst ; pCurr != pKth ; pCurr = pCurr->pNext) {
+            nEXIST += ArcCost( pCurr->nPos, pCurr->pNext->nPos) ;
+            nTEST += ArcCost( pCurr->pNext->nPos, pCurr->nPos) ;
+         }
+        // se lo scambio fa risparmiare
+         if ( nTEST < nEXIST) {
+           // inverto il tratto intermedio
+            for ( NODE* pCurr = pFirst ; pCurr != pKth ;) {
+               NODE* pSave = pCurr->pNext ;
+               pCurr->pNext = pCurr->pPrev ;
+               pCurr->pPrev = pSave ;
+               pCurr = pSave ;
+            }
+           // sistemo gli estremi
+            pFirst->pNext = pKth->pNext ;
+            pKth->pNext->pPrev = pFirst ;
+            pKth->pNext = pKth->pPrev ;
+            pKth->pPrev = pLast ;
+            pLast->pNext = pKth ;
+            pFirst = pLast->pNext ;
+            pKth = pFirst->pNext ;
+           // faccio ripartire il conto
+            nCount = 0 ;
+         }
+        // altrimenti passo al nodo successivo
+         else
+            pKth = pKth->pNext ;
+      } while ( pKth != pLast->pPrev->pPrev  &&  nCount != 0) ;
+      if ( nCount != 0)
+         pFirst = pFirst->pNext ;
+      nCount ++ ;
+      nTry ++ ;
+   } while ( nCount < m_nNumPnts  &&  nTry < MAX_TRY) ;
+
+  // ricalcolo il costo del percorso
+   return TotalCost( pPath) ;
+}
+