Submission #2177

#	Time	Username	Problem	Language	Result	Execution time	Memory
2177		cki86201	지우개 (GA4_eraser)	C++98	100 / 100	19 ms	4792 KiB

eraser

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

const int T=1e9+7;
long long int Dp[100010][4];
long long int A[100010];
int X,N;

int main()
{
	scanf("%d",&N);
	int i,j;
	for(i=1;i<=N;i++){
		int x;scanf("%d",&x);
		A[x]++;
		X=max(X,x);
	}
	for(i=1;i<=X;i++){A[i]*=i;A[i]%=T;}
	for(i=0;i<=X;i++)Dp[i][0]=1;
	for(j=1;j<=3;j++){
		for(i=1;i<=X;i++){
			Dp[i][j]=Dp[i-1][j]+Dp[i-1][j-1]*A[i];
			Dp[i][j]%=T;
		}
	}
	printf("%d",Dp[X][3]);
	return 0;
}

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