Submission #2165

#	Time	Username	Problem	Language	Result	Execution time	Memory
2165		jwvg0425	지우개 (GA4_eraser)	C++98	46 / 100	1000 ms	2840 KiB

eraser

#include<stdio.h>
#include<stdlib.h>
#include<algorithm>
#include<vector>
using namespace std;

#define MOD 1000000007
int n,r[100005];
long long int a[100005];
long long int v,s[100005];

int main()
{
	int i,j,k;
	scanf("%d",&n);
	for(i=0;i<n;i++)scanf("%lld",&a[i]);
	sort(&a[0],&a[n]);
	s[0]=a[0];
	for(i=1;i<n;i++)s[i]=s[i-1]+a[i];
	for(i=0;i<n;i++)
	{
		for(j=i+1;;j++)
		{
			if(a[j]!=a[i])
			{
				r[i]=j;
				break;
			}
		}
	}
	for(i=0;i<n;i++)
	{
		for(j=r[i];j<n-1;j++)
		{
			k=r[j];
			if(k<n)
			{
				v=(v+(s[n-1]-s[k-1])*(long long int)a[i]*(long long int)a[j])%MOD;
			}
		}
	}
	printf("%lld",v);
}

• Subtask 1: 6 / 6
• Subtask 2: 7 / 7
• Subtask 3: 16 / 16
• Subtask 4: 17 / 17
• Subtask 5: 0 / 26
• Subtask 6: 0 / 28