确定比赛名次 HDU - 1285 ，拓扑

#include<bits/stdc++.h>
using namespace std;
const int m = 500 + 5;
int g[m][m],indegree[m],topo[m];
int n;   //队伍数 
void tuopu()
{
    int k = 1;
    for(int i = 1; i <= n; i++)
    {
        int now;    //
        for(int j = 1; j <= n; j++)
        {
            if(indegree[j] == 0)    //寻找入度为0的点 
            {
                now = j;
                break;
            }
        }
        topo[k++] = now;    //存储 
        indegree[now] = -1;        //防止重复寻找 
        for(int j = 1; j <= n; j++)    //断掉与now相连的边,即与其相连的边的度数-1 
        {
            if(g[now][j] == 1)
            indegree[j]--;
        }
    }
    for(int j = 1; j < k-1; j++)
    cout<<topo[j]<<" ";
    cout<<topo[k-1]<<endl;
}
int main()
{
    int t;     //打的场次 
    while(~scanf("%d%d",&n,&t))
    {
        memset(g,0,sizeof(g));
        memset(indegree,0,sizeof(indegree));
        while(t--)
        {
            int a,b;
            cin>>a>>b;
            if(g[a][b] == 0)    //防止重复输入 
            {
                g[a][b] = 1;
                indegree[b]++;
            }
        }
        tuopu();
    }
    return 0;
}