Acdream 1017 Fast Transportation

http://acdream.info/problem?pid=1017

Test instructions: Give n points, M edge, K goods, from S to T, every day each side can only pass 1 times, begging for a few days to finish

Idea: Split the composition layer diagram, each layer down a layer of edge, note I can also connect to I, the flow is INF, represents this point of the van this day did not move

1#include <cstdio>2#include <iostream>3#include <cmath>4#include <algorithm>5#include <cstring>6 #defineINF 0x7fffffff7 structedge{8     intu,v;9}e[200005];Ten inttot,go[500005],next[500005],first[500005],op[500005],flow[500005],dis[500005],cnt[500005]; One intt,s,ss,tt,n,m,nodes,k; A intid[ the][ the]; - intRead () { -     intt=0, f=1;CharCh=GetChar (); the      while(ch<'0'|| Ch>'9'){if(ch=='-') f=-1; ch=GetChar ();} -      while('0'<=ch&&ch<='9') {t=t*Ten+ch-'0'; ch=GetChar ();} -     returnt*F; - } + voidInsertintXintYintz) { -tot++; +go[tot]=y; Anext[tot]=First[x]; atfirst[x]=tot; -flow[tot]=Z; - } - voidAddintXintYintz) { -Insert (x, y, z); op[tot]=tot+1; -Insert (Y,x,0); op[tot]=tot-1; in } - intDfsintXintf) { to     if(x==t)returnF; +     intmn=nodes,sum=0; -      for(intI=first[x];i;i=Next[i]) { the          intPur=Go[i]; *          if(flow[i]&&dis[pur]+1==Dis[x]) { $              intSave=dfs (Pur,std::min (flow[i],f-sum));Panax Notoginsengflow[i]-=Save; -flow[op[i]]+=Save; thesum+=Save; +              if(dis[s]>=nodes| | F==sum)returnsum; A          } the          if(Flow[i]) mn=std::min (Mn,dis[pur]); +     } -     if(sum==0){ $cnt[dis[x]]--; $         if(cnt[dis[x]]==0){ -dis[s]=nodes; -}Else{ thedis[x]=mn+1; -cnt[dis[x]]++;Wuyi         } the     } -     returnsum; Wu } - BOOLCheckintmid) { About      for(intI=0; i<=nodes;i++) first[i]=cnt[i]=dis[i]=0; tot=0; $     intsz=0; -      for(intI=1; i<=mid;i++) -          for(intj=1; j<=n;j++) -id[i][j]=++sz; At=sz+1; +sz+=2; thes=0; nodes=sz; -Add (s,id[1][ss],k); $      for(intI=1; i<=mid;i++) the Add (id[i][tt],t,k); the      for(intI=1; i<mid;i++) the       for(intj=1; j<=n;j++) theAdd (id[i][j],id[i+1][j],inf);  -      for(intI=1; i<=m;i++) in          for(intj=1; j<mid;j++) theAdd (id[j][e[i].u],id[j+1][E[I].V],1), Add (id[j][e[i].v],id[j+1][E[I].U],1); the     intans=0; About      while(Dis[s]<nodes) ans+=DFS (s,inf); the     returnans==J;  the } the intMain () { +      while(SCANF ("%d", &n)! =EOF) { -M=read (); K=read (); Ss=read (); tt=read (); the           for(intI=1; i<=m;i++)BayiE[i].u=read (), e[i].v=read (); the          intL=1, r=n+k+2, ans=0; the           while(l<=R) { -             intMid= (L+R)/2; -             if(Check (mid)) r=mid-1, ans=mid; the                 ElseL=mid+1; the           } theprintf"%d\n", ans-1); the     } -}

Acdream 1017 Fast Transportation