HDU 1285 確定比賽名次

題目大意：中文

題目鏈接

代碼：

/*                                 
 * Problem ID : HDU 1285 確定比賽名次
 * Author     : Lirx.t.Una                                 
 * Language   : C++                     
 * Run Time   : 15 ms                                 
 * Run Memory : 500 KB                                 
*/ 

#include <iostream>
#include <cstring>
#include <cstdio>
#include <queue>

#define	MAXN	500

using namespace std;

bool	g[MAXN + 1][MAXN + 1];
short	deg[MAXN + 1];

priority_queue<short, vector<short>, greater<short> >	heap;
queue<short>	ans;

void
topsort(int n) {

	int		i;
	int		u, v;

	for ( i = 1; i <= n; i++ )
		if ( !deg[i] ) {
		
			deg[i]--;
			heap.push(i);
		}

	while ( !heap.empty() ) {
	
		deg[ u = heap.top() ]--;
		ans.push(u);
		heap.pop();

		for ( v = 1; v <= n; v++ )
			if ( g[u][v] && !( --deg[v] ) )
				heap.push(v);
	}

	printf("%d", ans.front());
	ans.pop();
	while ( !ans.empty() ) {
	
		printf(" %d", ans.front());
		ans.pop();
	}
	putchar('\n');
}

int
main() {

	int		n, m;
	int		u, v;

	while ( ~scanf("%d%d", &n, &m) ) {
	
		memset(g, false, sizeof(g));
		memset(deg, 0, sizeof(deg));

		while ( m-- ) {
		
			scanf("%d%d", &u, &v);
			if ( !g[u][v] ) {

				g[u][v] = true;
				deg[v]++;
			}
		}

		topsort(n);
	}

	return 0;
}