1994.cpp

来自「哈尔滨工业大学ACM 竞赛网上在线试题集锦的源代码」· C++ 代码 · 共 29 行

/*  This Code is Submitted by wywcgs for Problem 1994 on 2006-02-21 at 12:18:58 */ 
#include <cstdio>
#include <algorithm>
using namespace std;

const int MAX = 1024;

int main()
{
	int t, T, i;
	int red[MAX];
	
	scanf("%d", &T);
	for(t = 0; t < T; t++) {
		int n, m, total = 0;
		scanf("%d %d", &n, &m);
		memset(red, 0, sizeof(red));
		for(i = 0; i < m; i++) {
			int a, b;
			scanf("%d %d", &a, &b);
			red[a-1]++; red[b-1]++;
		}
		for(i = 0; i < n; i++) total += red[i] * (n - 1 - red[i]);
		printf("%d\n", n*(n-1)*(n-2)/6-total/2);
	}
	
	return 0;
}