拓扑排序

#include<bits/stdc++.h>
using namespace std;
const int MAXN=30030;
bool vis[MAXN];
int in[MAXN];
int ans;
vector<int> edge[MAXN];
int main()
{
    int T;
    cin>>T;
    int n,m,a,b;
    while(T--)
    {
        scanf("%d%d",&n,&m);
        memset(in,0,sizeof(in));
        for (int i=1;i<=n;i++) edge[i].clear();
        for (int i=0;i<m;i++)
        {
            scanf("%d%d",&a,&b);
            in[a]++;
            edge[b].push_back(a);
        }
        priority_queue<int>q;
        for (int i=1;i<=n;i++)
        {
            if(!in[i])
            q.push(i);
        }
        vector<int>v;
        ans=0;
        while(!q.empty())
        {
            ans++;
            a=q.top();
            v.push_back(a);
            cout<<a<<" 进队"<<endl;
            q.pop();
            vis[a]=1;
            for (int i=0;i<edge[a].size();i++)
            {
                b=edge[a][i];
                in[b]--;
                if (!in[b]) q.push(b);
            }
        }
        for (int i=v.size()-1;i>=0;i--)
        {
            if (i!=v.size()-1) printf(" ");
            printf("%d",v[i]);
        }
        printf("\n");
    }
    return 0;
}