洛谷P3254 圆桌问题 网络流_二分图

Code:

#include<cstdio>

#include<algorithm>

#include<vector>

#include<queue>

#include<cstring>

using namespace std;

const int maxn=1004;

const int INF=10000000;

# define  pb push_back

int s,t;

struct Edge{

	int from,to,cap;

	Edge(int u,int v,int c):from(u),to(v),cap(c) {}

};

vector<Edge>edges;

vector<int>G[maxn];

struct Dicnic{

   int d[maxn],vis[maxn],cur[maxn];

   queue<int>Q;

   void addedge(int u,int v,int c){

   	edges.pb(Edge(u,v,c));               //正向弧

   	edges.pb(Edge(v,u,0));               //反向弧

   	int m=edges.size();

   	G[u].pb(m-2);

   	G[v].pb(m-1);

   }

   int BFS()

   {

    memset(vis,0,sizeof(vis));

    d[s]=0,vis[s]=1;Q.push(s);

    while(!Q.empty()){

    	int u=Q.front();Q.pop();

    	int sz=G[u].size();

    	for(int i=0;i<sz;++i){

    		Edge e=edges[G[u][i]];

    		if(!vis[e.to]&&e.cap>0){

    			d[e.to]=d[u]+1,vis[e.to]=1;

    			Q.push(e.to);

    		}

    	}

    }

    return vis[t];

   }

   int dfs(int x,int a){

       if(x==t)return a;

       int sz=G[x].size();

       int f,flow=0;

       for(int i=0;i<sz;++i){

       	Edge e=edges[G[x][i]];

          cur[x]=i;

       	if(d[e.to]==d[x]+1&&e.cap>0){

       		f=dfs(e.to,min(a,e.cap));

       		if(f)

       		{

       	      int u=G[x][i];

       	      a-=f;

                edges[u].cap-=f;

                edges[u^1].cap+=f;

                flow+=f;

                if(a==0)break;

       		}

       	}

       }

       return flow;

   }

   int maxflow(){

   	int ans=0;

   	while(BFS()){

      memset(cur,0,sizeof(cur));

      ans+=dfs(s,INF);

   	}

   	return ans;

   }

}op;

int main()

{

	int m,n,sum=0;

	scanf("%d%d",&m,&n);

	s=0,t=m+n+1;

     for(int i=1;i<=m;++i)

     {

     	    int a;scanf("%d",&a);

     	    op.addedge(s,i,a);

     	    sum+=a;

     	    for(int j=m+1;j<=m+n;++j)op.addedge(i,j,1);

     }

     for(int i=1;i<=n;++i)

     	{

         int a;scanf("%d",&a);

         op.addedge(i+m,t,a);

     	}

     	int F=op.maxflow();

     if(F!=sum){printf("0\n");return 0;}

     printf("1\n");

     for(int u=1;u<=m;++u)

     {

     	    int sz=G[u].size();

     	    for(int i=0;i<sz;++i)

     	    {

     	    	int e=G[u][i];

     	    	if(e%2==0&&edges[e].cap==0)printf("%d ",edges[e].to-m);

     	    }

     	    printf("\n");

     }

     return 0;

}