POJ 1975 (传递闭包)

Median Weight Bead - POJ 1975 - Virtual Judgehttps://vjudge.net/problem/POJ-1975#author=SCLchuck可以想到当大于这个或小于这个水滴的数目大于n/2时即可满足

int d[150][150];

void solve() {
	memset(d, 0, sizeof(d));
	int n, m;
	int x, y;
	scanf("%d %d", &n, &m);
	for (int i = 1; i <= m; i++) {
		scanf("%d %d", &x, &y);
		d[x][y] = 1;
	}
	for (int k = 1; k <= n; k++) {
		for (int i = 1; i <= n; i++) {
			for (int j = 1; j <= n; j++) {
				d[i][j] |= d[i][k] & d[k][j];
			}
		}
	}
	int ans = 0;
	for (int i = 1; i <= n; i++) {
		int tmp1 = 0, tmp2 = 0;
		for (int j = 1; j <= n; j++) {
			if (i == j)
				continue;
			tmp1 += d[i][j];
			tmp2 += d[j][i];
		}
		if (tmp1 > n / 2 || tmp2 > n / 2)
			ans++;
	}
	printf("%d\n", ans);
}