tyvj 1153 间谍网络 tarjan有向图强连通

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<vector>
using namespace std;
#define MAXN 10000
#define MAXE MAXN * 2
#define MAXV MAXN
#define INF 0x3f3f3f3f
int n,m;
struct Edge
{
        int np;
        Edge *next;
}E[MAXE],*V[MAXV];
int tope=-1;
void addedge(int x,int y)
{
        E[++tope].np=y;
        E[tope].next=V[x];
        V[x]=&E[tope];
}
int state[MAXN];
int value[MAXN];
int dfn[MAXN],low[MAXN],dfstime=0;
int stack[MAXN],tops=-1;
int color[MAXN],totc=0;
void tarjan(int now)
{
        low[now]=dfn[now]=++dfstime;
        Edge *ne;
        stack[++tops]=now;
        for (ne=V[now];ne;ne=ne->next)
        {
                if (dfn[ne->np])//state[ne->np]==1
                {
                        if (color[ne->np])continue;
                        low[now]=min(low[now],dfn[ne->np]);
                }else
                {
                        tarjan(ne->np);
                        low[now]=min(low[now],low[ne->np]);//易写反
                }
        }
        if (low[now]==dfn[now])
        {
                totc++;
                while (stack[tops]!=now)
                {
                        color[stack[tops--]]=totc;
                }
                color[stack[tops--]]=totc;
        }
}
int main()
{
//        freopen("input.txt","r",stdin);
//        freopen("output.txt","w",stdout);
        int t;
        int x,y;
        int i,j,k;
        scanf("%d",&n);
        memset(value,INF,sizeof(value));
        scanf("%d",&t);
        for (i=0;i<t;i++)
        {
                scanf("%d%d",&x,&y);
                value[x]=y;
        }
        scanf("%d",&m);
        for (i=0;i<m;i++)
        {
                scanf("%d%d",&x,&y);
                addedge(x,y);
        }
        for (i=1;i<=n;i++)
        {
                if (!dfn[i])
                {
                        tarjan(i);
                }
        }
        Edge *ne;
        for (i=1;i<=n;i++)
        {
                for (ne=V[i];ne;ne=ne->next)
                {
                        if (color[ne->np]==color[i])continue;
                        state[color[ne->np]]=true;
                }
        }
        x=INF;
        bool ok=true;
        int ans=0;
        int ans2=INF;
        for (i=1;i<=totc;i++)
        {
                if (state[i])continue;
                x=INF;
                for (j=1;j<=n;j++)
                {
                        if (color[j]!=i)continue;
                        x=min(x,value[j]);
                }
                if (x==INF)
                {
                        ok=false;
                        for (j=1;j<=n;j++)
                        {
                                if (color[j]==i)
                                {
                                        ans2=min(ans2,j);
                                        break;
                                }
                        }
                }
                ans+=x;
        }
        if (!ok)
        {
                printf("NO\n%d\n",ans2);
        }else
        {
                printf("YES\n%d\n",ans);
        }
}