Submission #19493

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
19493	2016-02-24T14:11:06 Z	noslaak	Σ (kriii4_P2)	C++	100 / 100	15 ms	1720 KB

P2

#include <iostream>

const int LN = 1000000007;
int modpow( long long A, long long X )
{
	int acc = 1;
	while(X)
	{
		A %= LN;
		if(X%2)
			acc = (A*acc)%LN;
			
		A = A*A;
		X /= 2;
	}

	return acc;
}


int main()
{
	int M;
	while( std::cin >> M )
	{
		int N, S, acc = 0;
		for( int i = 0; i < M; ++i )
		{
			std::cin >> N >> S;
			int rev = modpow(N, LN-2);
			int ans = ((long long)S*rev)%LN;
			acc = (acc+ans)%LN;
		}
		std::cout << acc << std::endl;
	}

	return 0;
}

Subtask #1

100.0 / 100.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	13 ms	1720 KB	Output is correct
2	Correct	14 ms	1720 KB	Output is correct
3	Correct	14 ms	1720 KB	Output is correct
4	Correct	13 ms	1720 KB	Output is correct
5	Correct	13 ms	1720 KB	Output is correct
6	Correct	14 ms	1720 KB	Output is correct
7	Correct	14 ms	1720 KB	Output is correct
8	Correct	15 ms	1720 KB	Output is correct
9	Correct	15 ms	1720 KB	Output is correct
10	Correct	11 ms	1720 KB	Output is correct
11	Correct	14 ms	1720 KB	Output is correct
12	Correct	13 ms	1720 KB	Output is correct
13	Correct	13 ms	1720 KB	Output is correct
14	Correct	15 ms	1720 KB	Output is correct
15	Correct	13 ms	1720 KB	Output is correct
16	Correct	12 ms	1720 KB	Output is correct
17	Correct	15 ms	1720 KB	Output is correct
18	Correct	11 ms	1720 KB	Output is correct
19	Correct	15 ms	1720 KB	Output is correct
20	Correct	13 ms	1720 KB	Output is correct