UVA 11806 - Cheerleaders（数论+容斥原理）

#include <stdio.h>
#include <string.h>

const int MOD = 1000007;
const int N = 505;
int t, n, m, k, C[N][N];

int main() {
	C[0][0] = 1;
	for (int i = 0; i < N; i++) {
		C[i][0] = C[i][i] = 1;
		for (int j = 1; j < i; j++)
			C[i][j] = (C[i - 1][j] + C[i - 1][j - 1]) % MOD;
	}
	int cas = 0;
	scanf("%d", &t);
	while (t--) {
		int sum = 0;
		scanf("%d%d%d", &n, &m, &k);
		for (int s = 0; s < 16; s++) {
			int count = 0, r = n, c = m;
			if (s&1) {count++; r--;}
			if (s&2) {count++; r--;}
			if (s&4) {count++, c--;}
			if (s&8) {count++, c--;}
			if (count&1) sum = (sum - C[r * c][k] + MOD) % MOD;
			else sum = (sum + C[r * c][k]) % MOD;
		}
		printf("Case %d: %d\n", ++cas, sum);
	}
	return 0;
}