Submission #19485

#	Time	Username	Problem	Language	Result	Execution time	Memory
19485		zych1751	Σ (kriii4_P2)	C++98	100 / 100	7 ms	1084 KiB

P2

#include<cstdio>

const int INF = 1e9+7;

long long mod(long long a) // a^(x-2)
{
	int mul = 1e9+5;
	long long result = 1;
	a %= INF;

	while(mul)
	{
		if(mul & 1)
			result = (result * a) % INF;
		a = (a*a) % INF;
		mul /= 2;
	}
	return result;
}

int main()
{
	int m;
	long long n, s;
	long long result = 0;

	scanf("%d", &m);
	for(int i = 0; i < m; i++)
	{
		scanf("%lld %lld", &n, &s);
		result += s * mod(n);
		result %= INF;
	}
	printf("%lld", result);
}

• Subtask 1: 100 / 100