Submission #20126

#	Time	Username	Problem	Language	Result	Execution time	Memory
20126		progressive	로봇 (kriii4_F)	C++14	4 / 100	1000 ms	1084 KiB

F

#include<cstdio>
const int MOD = 1000000007;
long long powM(long long a, long long b)
{
	if(b==1) return a;
	if(b%2==1) return a*powM(a,b-1)%MOD;
	return powM(a,b/2)*powM(a,b/2)%MOD;
}
int main()
{
	long long sum_xi = 0;
	long long sum_yi = 0;
	long long sum_square = 0;
	long long LMRN = 1;
	int N, L, M, R;
	scanf("%d%d%d%d",&N,&L,&M,&R);
	for(int i=0; i<N; i++)
	{
		LMRN = LMRN*(L+M+R)%MOD;
		long long new_xi = (((L-R)*sum_yi+M*sum_xi+LMRN)%MOD+MOD)%MOD;
		long long new_yi = (((R-L)*sum_xi+M*sum_yi)%MOD+MOD)%MOD;
		long long new_square = (((L+M+R)*sum_square+LMRN+2*(L-R)*sum_yi + 2*M*sum_xi)%MOD+MOD)%MOD;
		sum_xi = new_xi;
		sum_yi = new_yi;
		sum_square = new_square;
	}
	printf("%lld",sum_square*powM(LMRN,MOD-2)%MOD);
}

• Subtask 1: 4 / 4
• Subtask 2: 0 / 96