hdu1285拓扑排序

#include <cstdio>#include <iostream>#include <cstring>using namespace std;int N, M, a, b, num;bool map[510][510];int temp[510], ans[510];int main(){while(scanf("%d %d", &N, &M)!= EOF){memset(temp, 0, sizeof(temp));memset(ans, 0, sizeof(ans));memset(map, 0, sizeof(map));num = 0;for(int i = 1; i <= M; i++){cin >> a >> b;if(!map[a][b]){temp[b] ++;}map[a][b] = true;}while(num <= N){int j = 1;while(temp[j] != 0){j++;if(j > N){break;}}temp[j] = -1;ans[num] = j;num++;for(int i = 1; i <= N; i++){if(map[j][i]){map[j][i] = false;temp[i]--;}}}for(int i = 0; i < num - 1; i++){if(i == num - 2){cout << ans[i] << endl;break;}cout << ans[i] << " ";}}return 0;}