zoj 2429 Destroying The Graph 最小点权覆盖

 

#include <cstdio>
#include <string.h>
#include <vector>
using namespace std;
#define Max 230
#define INF 100000000
int flow[Max][Max],d[Max];
int vis[Max*3];
int sta,end; 
vector <int> sum;
int min(int a,int b)
{
    if(a<b) return a;
    else return b;
}
void dfs(int u)
{
	int i,k;
	vis[u]=1;
	for(i=0;i<=end;i++)
	{
		if(!vis[i]&&flow[u][i])
			dfs(i);
	}
}
bool bfs(int s)
{
    int front=0,rear=0; 
    int q[Max*100];
    int k,i;
    memset(d,-1,sizeof(d)); 
    q[rear++]=s;  d[s]=0;
    while(front<rear)
    {
        k=q[front++];
        for(i=1;i<=end;i++)
            if(flow[k][i]>0&&d[i]==-1)
            {
                d[i]=d[k]+1;
                q[rear++]=i;
            }
    }
    if(d[end]>=0)   return true;
    return false;
}

int dinic(int k,int sum)
{
    int i,a;
    if(k==end)    return sum;
    int os=sum;
    for(i=1;i<=end&∑i++)
        if(d[i]==d[k]+1&&flow[k][i]>0)
        {
            a=dinic(i,min(sum,flow[k][i])); 
            flow[k][i]-=a;
            flow[i][k]+=a;
            sum-=a;
        }
    return os-sum;
}
int main()
{
	int w1[120],w2[120];
	int n,m;
	int i,t;
	scanf("%d",&t);
	while(t--)
	{
		int x,y;
		int ans=0;
		memset(flow,0,sizeof(flow));
		scanf("%d%d",&n,&m);	
		sta=0;end=2*n+1;
		for(i=1;i<=n;i++)
			scanf("%d",&w1[i]);
		for(i=1;i<=n;i++)
			scanf("%d",&w2[i]);
		for(i=1;i<=n;i++) flow[i+n][end]=w1[i];
		for(i=1;i<=n;i++) flow[sta][i]=w2[i];
		for(i=1;i<=m;i++)
		{
			scanf("%d%d",&x,&y);
			flow[x][y+n]=INF;
		}
		while(bfs(sta))
			ans+=dinic(sta,INF);
		printf("%d\n",ans);
		memset(vis,0,sizeof(vis));
		dfs(0);
		sum.clear();
		for(i=1;i<=n;i++)
		{
			if(!vis[i]) sum.push_back(i);
			if(vis[i+n]) sum.push_back(i+n);
		}
		printf("%d\n",sum.size());
		for(i=0;i<sum.size();i++)
		{
			if(sum[i]<=n) printf("%d-\n",sum[i]);
			else printf("%d+\n",sum[i]-n);
		}
		printf("\n");
	}
	return 0;
}