2330065_wa.cpp

北大大牛代码 1240道题的原代码 超级权威

#include <algorithm>

using namespace std;

struct node
{
	long t, d;
}cow[100001];

bool cmp(struct node a,struct node b)
{
	return a.t*b.d<b.t*a.d;
}

int main()
{
	long i, n;
	long ans, sum, tmp;

	scanf("%ld",&n);
	sum = 0;
	for(i = 0; i < n; i++)
	{
		scanf("%ld%ld",&cow[i].t,&cow[i].d);
		sum += cow[i].d;
	}
	tmp = 0;
	sort(cow,cow+n,cmp);
	ans = 0;
	for(i = 0; i < n; i++)
	{
		tmp += cow[i].d;
		ans += 2*cow[i].t*(sum - tmp);
	}
	printf("%ld\n",ans);
	return 1;
}