1781.cpp

这是哈尔滨工业大学acmOJ的源代码

/* This Code is Submitted by wywcgs for Problem 1781 on 2007-05-06 at 15:14:19 */
#include <cstdio>
#include <algorithm>
using namespace std;

const int N = 10240;

int main()
{
	int rs[N], T;
	scanf("%d", &T);
	for(int t = 0; t < T; t++) {
		int n, m; scanf("%d %d", &n, &m);
		for(int i = 0; i < n; i++) rs[i] = 2;
		for(int i = 0; i < m; i++) {
			int a, b; scanf("%d %d", &a, &b); a--; b--;
			if(rs[b] == 0) continue;
			if(rs[a] < 2) { rs[a] = rs[b]; rs[b]--; }
			else rs[b]--;
		}
		int res = 0;
		for(int i = 1; i < n; i++) res += rs[i];
		printf("%d\n", res);
	}
	return 0;
}