Reactor Cooling ZOJ - 2314 上下界网络流

Posted 2021-02-09 guangheli

Code:

#include<cstdio>
#include<algorithm>
#include<vector>
#include<queue>
#include<iostream>
#include<cstring>
using namespace std;
const int maxn=600;
const int INF=1000000;
# define  pb push_back
int A[maxn],mapp[INF],bass[INF];
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;
 struct Dicnic{
   vector<int>G[maxn];
   int d[maxn],vis[maxn],cur[maxn];
   queue<int>Q;
   void init(){
   	for(int i=0;i<maxn;++i)G[i].clear();
   	edges.clear();
   }
   void addedge(int u,int v,int c,int cnt){
   	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);
   	if(cnt>0)mapp[cnt]=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=cur[x];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 T;cin>>T;
     s=0,t=420;
    for(int cas=1;cas<=T;++cas){
    	memset(A,0,sizeof(A));
    	op.init();
	int n,m,sum=0;
	cin>>n>>m;
	for(int i=1;i<=m;++i){
		int a,b,c,d;
		cin>>a>>b>>c>>d;
		bass[i]=c;
		op.addedge(a,b,d-c,i);                            
		A[a]-=c,A[b]+=c;
	}
            for(int i=1;i<=m;++i){
            	             if(A[i]>0){op.addedge(s,i,A[i],0);sum+=A[i];}
            	             if(A[i]<0)op.addedge(i,t,-A[i],0);
            }
            int  flow=op.maxflow();
            if(flow==sum){
            	      cout<<"YES"<<endl;
            	      for(int i=1;i<m;++i)cout<<edges[mapp[i]].cap+bass[i]<<endl;
            	      cout<<edges[mapp[m]].cap+bass[m];
            	     if(cas!=T)cout<<endl;
            }else cout<<"NO"<<endl;
            if(cas!=T)cout<<endl;
      }
      return 0;
}