Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 13320    Accepted Submission(s): 5328
#include<iostream>
#include<cstdio>
#include<cmath>
#include<vector>
#include<cstring>
#include<string>
using namespace std;
#define INF 1<<30
vector<int> e[510],ans;
int n,m,in[510];
int main()
{
      int x,y;
      while(scanf("%d%d",&n,&m)!=EOF)
      {
            memset(in,0,sizeof(in));
            ans.clear();
            for(int i=0;i<510;i++)
                  e[i].clear();
            for(int i=1;i<=m;i++)
            {
                  scanf("%d%d",&x,&y);
                  e[x].push_back(y);
                  in[y]++;
            }
            for(int i=1;i<=n;i++)
            {
                  int j=1;
                  while(j<=n&&in[j]!=0) j++;
                  if(j<=n) ans.push_back(j);
                  in[j]=INF;
                  for(int k=0;k<e[j].size();k++)
                        in[e[j][k]]--;
            }
            printf("%d",ans[0]);
            for(int i=1;i<ans.size();i++)
                  printf(" %d",ans[i]);
            printf("\n");
      }
      return 0;
}
原文:http://www.cnblogs.com/a972290869/p/4227652.html