nyoj 120 建边构强连通

#include<stdio.h>
#include<string.h>
#include<queue>
using namespace std;
#define  N  200

struct node
{
    int u,v,next;
} bian[N*N];
int n,dfn[N],low[N],stac[N],yong,head[N],visit[N],ans,top,inde,suo[N],indegree[N],outdegree[N];
void init()
{
    memset(dfn,0,sizeof(dfn));
    memset(low,0,sizeof(low));
    memset(head,-1,sizeof(head));
    memset(stac,0,sizeof(stac));
    memset(visit,0,sizeof(visit));
    memset(suo,0,sizeof(suo));
    memset(indegree,0,sizeof(indegree));
    memset(outdegree,0,sizeof(outdegree));
    ans=0;
    yong=0;
    top=0;
    inde=0;
}
void addedge(int u,int v)
{
    bian[yong].u=u;
    bian[yong].v=v;
    bian[yong].next=head[u];
    head[u]=yong++;
}
int Max(int a,int b)
{
    return a>b?a:b;
}
int Min(int a,int b)
{
    return a>b?b:a;
}
void tarjan(int u)
{
    dfn[u]=low[u]=++inde;
    stac[++top]=u;
    visit[u]=1;
    int i;
    for(i=head[u]; i!=-1; i=bian[i].next)
    {
        if(!dfn[bian[i].v])
        {
            tarjan(bian[i].v);
            low[u]=Min(low[u],low[bian[i].v]);
        }
        else if(visit[bian[i].v]==1)
            low[u]=Min(low[u],dfn[bian[i].v]);

    }
    if(dfn[u]==low[u])
    {
        ans++;
        int t;
        do
        {
            t=stac[top--];
            visit[t]=2;
            suo[t]=ans;
        }
        while(t!=u);
    }
}
int main()
{
    int t,n,m,i,fin,fout;
    scanf("%d",&t);
    while(t--)
    {
        scanf("%d",&n);
        init();
        for(i=1; i<=n; i++)
        {
            while(scanf("%d",&m),m)
                addedge(i,m);
        }
        for(i=1; i<=n; i++)
            if(visit[i]!=2)
                tarjan(i);
            if(ans==1) {//important
                printf("0\n");
                continue;
            }
     for(i=0;i<yong;i++)
     if(suo[bian[i].u]!=suo[bian[i].v]) {
        indegree[suo[bian[i].u]]++;
        outdegree[suo[bian[i].v]]++;
     }
        fin=0;
        fout=0;
        for(i=1; i<=ans; i++)
        {
            if(indegree[i]==0)
                fin++;
            if(outdegree[i]==0)
                fout++;
        }
        printf("%d\n",Max(fin,fout));
    }

    return 0;
}