spoj 839 最小割+二进制

#include<stdio.h>
#include<string.h>
#include<queue>
using namespace std;
#define inf 0x3fffffff
#define  N  550
struct node {
 int u,v,w,next;
}bian[N*20],ff[N*20],fk[N];
int vis[N];
int head[N],yong,dis[N],work[N];
int ans[N];
void init() {
yong=0;
memset(head,-1,sizeof(head));
}
void addedge(int u,int v,int w) {
bian[yong].v=v;
bian[yong].w=w;
bian[yong].next=head[u];
head[u]=yong++;
}
int bfs(int s,int t)
{
    memset(dis,-1,sizeof(dis));
    queue<int>q;
    q.push(s);
    dis[s]=0;
    while(!q.empty())
    {
        int u=q.front();
        q.pop();
        for(int i=head[u];i!=-1;i=bian[i].next)
        {
            int v=bian[i].v;
            if(bian[i].w&&dis[v]==-1)
            {
                dis[v]=dis[u]+1;
                q.push(v);
                if(v==t)
                    return 1;
            }
        }
    }
    return 0;
}
int dfs(int  s,int limit,int t)
{
    if(s==t)return limit;
    for(int &i=work[s];i!=-1;i=bian[i].next)
    {
        int v=bian[i].v;
        if(bian[i].w&&dis[v]==dis[s]+1)
        {
            int tt=dfs(v,min(limit,bian[i].w),t);
            if(tt)
            {
                bian[i].w-=tt;
                bian[i^1].w+=tt;
                return tt;
            }
        }
    }
    return 0;
}
int dinic(int s,int t)
{
    int ans=0;
    while(bfs(s,t))
    {
        memcpy(work,head,sizeof(head));
        while(int tt=dfs(s,inf,t))
            ans+=tt;
    }
    return ans;
}
void build(int t,int m,int kk,int f) {
  init();
  int i;
  for(i=1;i<=m;i++) {
    addedge(ff[i].u,ff[i].v,1);
    addedge(ff[i].v,ff[i].u,1);
  }
  for(i=1;i<=kk;i++) {
    if(fk[i].v&(1<<f)) {
        addedge(0,fk[i].u,inf);
        addedge(fk[i].u,0,0);
    }
    else {
        addedge(fk[i].u,t,inf);
        addedge(t,fk[i].u,0);
    }
  }
  return ;
}

void dfs1(int u,int kk) {
   int i;
   vis[u]=1;
   for(i=head[u];i!=-1;i=bian[i].next) {
    int v=bian[i].v;
    if(!vis[v]&&bian[i].w) {
        ans[v]|=(1<<kk);
        dfs1(v,kk);
    }
   }
   return ;
}
void print() {
 int i;
 for(i=0;i<yong;i++)
    printf("%d %d %d
",bian[i].u,bian[i].v,bian[i].w);
}
int main() {
     int n,m,i,kk,t,k;
     scanf("%d",&t);
     while(t--) {
        scanf("%d%d",&n,&m);
        for(i=1;i<=m;i++)
            scanf("%d%d",&ff[i].u,&ff[i].v);
        scanf("%d",&kk);
        for(i=1;i<=kk;i++)
            scanf("%d%d",&fk[i].u,&fk[i].v);
        memset(ans,0,sizeof(ans));
        for(k=0;k<31;k++) {
            build(n+1,m,kk,k);
          //  print();break;
            dinic(0,n+1);
          // printf("%d
",dinic(0,n+1));
            memset(vis,0,sizeof(vis));
            dfs1(0,k);
        }
        for(i=1;i<=n;i++)
            printf("%d
",ans[i]);
     }
return 0;}


原文地址:https://www.cnblogs.com/thefirstfeeling/p/4410552.html