题目1449：确定比赛名次

#include<stdio.h>

#include<vector>

#include<queue>

using namespace std;

vector<int> edge[501];

priority_queue<int, vector<int>,greater<int> > Q; // 小顶堆

int main()

{

int inDegree[501];

int n,m;

while(scanf("%d%d",&n,&m)!=EOF){

for(int i=1;i<=n;i++){

inDegree[i]=0; edge[i].clear();

}

while(m--){

int a,b;

scanf("%d%d",&a,&b);

inDegree[b]++;

edge[a].push_back(b);

}

while(Q.empty()==false) Q.pop();

for(int i=1;i<=n;i++){

if(inDegree[i]==0) Q.push(i);

}

int cnt=0;

while(Q.empty()==false){

int nowP=Q.top();

if(cnt!=n-1) printf("%d ",nowP);

else printf("%d\n",nowP);

Q.pop();

cnt++;

for(int i=0;i<edge[nowP].size();i++){

inDegree[edge[nowP][i]]--;

if(inDegree[edge[nowP][i]]==0){

Q.push(edge[nowP][i]);

}

}

}

}

return 0;

}