HDU 4292:food (maximum flow)

http://acm.hdu.edu.cn/showproblem.php?pid=4292

Test instructions: It's almost like a cow, but there are a variety of foods.

Idea: Because of the variety of food, so the source and meeting point capacity to be changed. and Dinic and Tle, with ISAP.

#include <cstdio>#include<algorithm>#include<iostream>#include<cstring>#include<string>#include<cmath>#include<queue>#include<vector>#include<map>#include<Set>using namespacestd;#defineINF 0x3f3f3f3f#defineN 910typedefLong LongLl;typedefLong LongLL;structEdge {intV, Cap, NXT; Edge () {} Edge (intVintCapintNXT): V (v), cap (CAP), NXT (NXT) {}}edge[n*N];inttot, Cur[n], dis[n], pre[n], head[n], gap[n], S, T;voidADD (intUintVintcap) {Edge[tot]= Edge (V, Cap, Head[u]); Head[u] = tot++; Edge[tot]= Edge (U,0, Head[v]); HEAD[V] = tot++;}voidBFS () {Queue<int>que;  while(!que.empty ()) Que.pop (); memset (DIS,-1,sizeof(DIS)); Memset (Gap,0,sizeof(GAP)); Dis[t]=0; gap[0]++; Que.push (T);  while(!Que.empty ()) {        intU =Que.front (); Que.pop ();  for(inti = Head[u]; ~i; i =edge[i].nxt) {            intv =edge[i].v; if(Dis[v] = =-1)Continue; DIS[V]= Dis[u] +1; GAP[DIS[V]]++;        Que.push (v); }    }}intISAP (intN) {memcpy (cur, head,sizeof(cur));    BFS (); intU = pre[s] = S, ans =0, I;  while(Dis[s] <N) {if(U = =T) {intFlow =INF, index;  for(inti = S; I! = T; i =edge[cur[i]].v) {Edge& e =Edge[cur[i]]; if(E.cap <flow) {Flow= E.cap; index =i; }            }             for(inti = S; I! = T; i =edge[cur[i]].v) {Edge[cur[i]].cap-=flow; Edge[cur[i]^1].cap + =flow; } ans+ = flow; U =index; }         for(i = cur[u]; ~i; i =edge[i].nxt)if(DIS[EDGE[I].V] = = Dis[u]-1&& Edge[i].cap >0)                 Break; if(~i) {Cur[u]=i; PRE[EDGE[I].V]=u; U=edge[i].v; } Else {            intMD =N; if(--gap[dis[u]] = =0) Break;  for(inti = Head[u]; ~i; i =edge[i].nxt) {                if(MD > DIS[EDGE[I].V] && edge[i].cap >0) {MD= DIS[EDGE[I].V]; Cur[u] =i; }            }            ++GAP[DIS[U] = MD +1]; U=Pre[u]; }    }    returnans;}intMain () {intN, F, D;  while(~SCANF ("%d%d%d", &n, &f, &d)) {S=0, T =2* n + F + D +1; memset (Head,-1,sizeof(head)); Tot=0;intAChars[ -];  for(inti =1; I <= F; i++) {scanf ("%d", &a); ADD (S, I+2*N, a); }         for(inti =1; I <= D; i++) {scanf ("%d", &a); ADD (i+2* n +F, T, a); }         for(inti =1; I <= N; i++) {Add (I, I+ N,1); scanf ("%s", S +1);  for(intj =1; J <= F; J + +) {                if(S[j] = ='Y') {ADD (2* n + j, I,1); }            }        }         for(inti =1; I <= N; i++) {scanf ("%s", S +1);  for(intj =1; J <= D; J + +) {                if(S[j] = ='Y') {ADD (i+ N,2* n + j + F,1); }}} printf ("%d\n", ISAP (T +1)); }    return 0;}

HDU 4292:food (maximum flow)