HUST1024 Dance Party (Max Stream)

The topic probably said that there are N men n women, every round of men to dance with different women, men and women have their own likes to dance with the object, they can tolerate and k not like the people dance, ask the ball can be a few rounds.

Binary enumeration round with maximum flow judgment: male and female each split into two points I, I ' and J, J ', the side of the middle continuous volume k; the edge of the source point to I with the number of rounds, J ' to the edge of the meeting point of the number of rounds; if I and J are like relations then I to the side of the J ' even capacity 1, otherwise I ' to the side of the J-1; If the result equals n the number of rounds is set.

1#include <cstdio>2#include <cstring>3#include <queue>4#include <algorithm>5 using namespacestd;6 #defineINF (1&LT;&LT;30)7 #defineMAXN 4448 #defineMAXM 444*8889 Ten structedge{ One     intV,cap,flow,next; A }EDGE[MAXM]; - intVs,vt,ne,nv; - intHEAD[MAXN]; the  - voidAddedge (intUintVintcap) { -Edge[ne].v=v; Edge[ne].cap=cap; edge[ne].flow=0; -Edge[ne].next=head[u]; head[u]=ne++; +Edge[ne].v=u; edge[ne].cap=0; edge[ne].flow=0; -EDGE[NE].NEXT=HEAD[V]; head[v]=ne++; + } A  at intLEVEL[MAXN]; - intGAP[MAXN]; - voidBFs () { -memset (level,-1,sizeof(level)); -Memset (Gap,0,sizeof(GAP)); -level[vt]=0; ingap[level[vt]]++; -queue<int>que; to Que.push (VT); +      while(!Que.empty ()) { -         intu=Que.front (); Que.pop (); the          for(intI=head[u]; i!=-1; I=Edge[i].next) { *             intv=edge[i].v; $             if(level[v]!=-1)Continue;Panax Notoginsenglevel[v]=level[u]+1; -gap[level[v]]++; the Que.push (v); +         } A     } the } +  - intPRE[MAXN]; $ intCUR[MAXN]; $ intIsap () { - BFS (); -memset (pre,-1,sizeof(pre)); thememcpy (Cur,head,sizeof(head)); -     intu=pre[vs]=vs,flow=0, aug=INF;Wuyigap[0]=NV; the      while(level[vs]<NV) { -         BOOLflag=false; Wu          for(int&i=cur[u]; i!=-1; I=Edge[i].next) { -             intv=edge[i].v; About             if(Edge[i].cap!=edge[i].flow && level[u]==level[v]+1){ $flag=true; -pre[v]=u; -u=v; -                 //aug= (Aug==-1?edge[i].cap:min (Aug,edge[i].cap)); AAug=min (aug,edge[i].cap-edge[i].flow); +                 if(v==VT) { theflow+=; -                      for(u=pre[v]; V!=vs; v=u,u=Pre[u]) { $edge[cur[u]].flow+=; theedge[cur[u]^1].flow-=; the                     } the                     //Aug=-1; theaug=INF; -                 } in                  Break; the             } the         } About         if(flag)Continue; the         intMinlevel=NV; the          for(intI=head[u]; i!=-1; I=Edge[i].next) { the             intv=edge[i].v; +             if(Edge[i].cap!=edge[i].flow && level[v]<minlevel) { -Minlevel=Level[v]; thecur[u]=i;Bayi             } the         } the         if(--gap[level[u]]==0) Break; -level[u]=minlevel+1; -gap[level[u]]++; theu=Pre[u]; the     } the     returnflow; the } - intn,m,k; the BOOLg[111][111]; the //vs I i+n i+2*n i+3*n vt the BOOLisOKintt) {94Xss0; vt=n*4+1; nv=vt+1; Ne=0; thememset (head,-1,sizeof(head)); the      for(intI=1; i<=n; ++i) { the Addedge (vs,i,t);98Addedge (i,i+n,k); AboutAddedge (i+2*n,i+3*n,k); -Addedge (i+3*n,vt,t);101     }102      for(intI=1; i<=n; ++i) {103          for(intj=1; j<=n; ++j) {104             if(G[i][j]) Addedge (i,j+3*n,1); the             ElseAddedge (i+n,j+2*n,1);106         }107     }108     returnISAP () ==t*N;109 } the intMain () {111     intt,a,b; thescanf"%d",&t);113      while(t--){ thescanf"%d%d%d",&n,&m,&k); thememset (G,0,sizeof(G)); the          while(m--){117scanf"%d%d",&a,&b);118g[a][b]=1;119         } -         intL=0, r=N;121          while(l<R) {122             intmid=l+r+1>>1;123             if(isOK (mid)) l=mid;124             Elser=mid-1; the         }126printf"%d\n", L);127     } -     return 0;129}

HUST1024 Dance Party (Max Stream)