HDU 3046 min. cut

Each fence is actually a side, repair some fences, so that the wolf can not catch the sheep, in fact, is to seek a cut, so that the sheep all in S, the wolves are all in T.

1#include <cstdio>2#include <cstring>3#include <vector>4#include <queue>5 #defineMAXN 400106 #defineOO 0x3f3f3f3f7 #defineCLR (arr,n) memset (&arr,0,sizeof (arr[0]) * (n+1))8 using namespacestd;9 Ten structEdge { One     intu, V, F; AEdge (intUintVintf): U (U), V (v), F (f) {} - }; - structDinic { the     intN, SRC, DST; -Vector<edge>Edge; -vector<int>G[MAXN]; -     intDEP[MAXN], CUR[MAXN]; +      -     voidInitintNintSrcintDST) { +          This->n =N; A          This-&GT;SRC =src; at          This-&GT;DST =DST; -          for(intu=1; u<=n; u++ ) - g[u].clear (); - edge.clear (); -     } -     voidAdd_edge (intUintVintf) { in G[u].push_back (Edge.size ()); - Edge.push_back (Edge (u,v,f)); to G[v].push_back (Edge.size ()); +Edge.push_back (Edge (V,u,0) ); -     } the     BOOLBFs () { *queue<int>Qu; $ CLR (DEP, N);Panax Notoginseng Qu.push (SRC); -DEP[SRC] =1; the          while( !Qu.empty ()) { +             intu=Qu.front (); A Qu.pop (); the              for(intt=0; T<g[u].size (); t++ ) { +Edge &e=Edge[g[u][t]]; -                 if(E.F &&!)DEP[E.V]) { $DEP[E.V] = dep[e.u]+1; $ Qu.push (E.V); -                 } -             } the         } -         returnDEP[DST];Wuyi     } the     intDfsintUinta) { -         if(U==DST | | a==0)returnA; Wu         intRemain=a, past=0, na; -          for(int&t=cur[u]; T<g[u].size (); t++ ) { AboutEdge &e =Edge[g[u][t]]; $Edge &ve = edge[g[u][t]^1]; -             if(E.f && dep[e.v]==dep[e.u]+1&& (na=Dfs (E.v,min (e.f,remain)))) { -Remain-=na; -Past + =na; AE.F-=na; +Ve.f + =na; the                 if(remain==0) Break; -             } $         } the         returnpast; the     } the     intMaxflow () { the         intFlow =0; -          while(BFS ()) { in CLR (cur, n); theFlow + =DFS (src,oo); the         } About         returnflow; the     } the }; the  + intN, M; - intidx[ About][ About], Id_clock; the intmap[ About][ About];Bayi intdx[2] = { +1,0 }; the intdy[2] = {0, +1 }; the dinic D; -  - intMain () { the      for(intcas=1; ; cas++ ) { the         if(SCANF ("%d%d", &n, &m)! =2)return 0; theId_clock =0; the          for(intI=1; i<=n; i++ )  -              for(intj=1; j<=m; J + + ) { thescanf"%d", &map[i][j]); theIDX[I][J] = + +Id_clock; the             }94D.init (id_clock+2, id_clock+1, id_clock+2 ); the          for(intI=1; i<=n; i++ ) the              for(intj=1; j<=m; J + + )  the                  for(intD=0; d<2; d++ ) {98                     intNI = i+Dx[d]; About                     intNJ = j+Dy[d]; -                     if(1<=ni&&ni<=n &&1<=nj&&nj<=m) {101                         intU =Idx[i][j];102                         intv =Idx[ni][nj];103D.add_edge (U, V,1 );104D.add_edge (V, U,1 ); the                     }106                 }107          for(intI=1; i<=n; i++ )108              for(intj=1; j<=m; J + + ) {109                 if(map[i][j]==1 )  the D.add_edge (D.SRC, idx[i][j], oo);111                 if(map[i][j]==2 ) the D.add_edge (Idx[i][j], D.DST, oo);113             } theprintf"Case %d:\n%d\n", CAs, D.maxflow ()); the     } the}

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HDU 3046 min. cut