2183902_re.cc

北大大牛代码 1240道题的原代码 超级权威

# include <cstdio>
# include <algorithm>

using namespace std;

void input()
{
	long i, j, n;
	long ans, tmp;
	long a[4001], b[4001], c[4001], d[4001];
	long A[4000*4000+1], B[4000*4000+1];

	scanf("%ld",&n);
	ans = tmp = 0;
	for(i = 0; i < n; i++)
		scanf("%ld%ld%ld%ld",&a[i],&b[i],&c[i],&d[i]);
	for(i = 0; i < n; i++)
		for(j = 0; j < n; j++)
		{
			A[i*n+j] = a[i]+b[j];
			B[i*n+j] = c[i]+d[j];
		}
	sort(A,A+n*n);
	sort(B,B+n*n);
	for(i = 0, j = n*n-1; i < n*n; i++)
	{
		if(i&&A[i]==A[i-1])
			ans += tmp;
		else
		{
			tmp = 0;
			while(j>=0&&B[j]>-A[i])
				j--;
			while(j>=0&&B[j]==-A[i])
				j--,ans++,tmp++;
		}
	}
	printf("%d\n",ans);
}

int main()
{
	input();
	return 1;
}