답안 #19310

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
19310	2016-02-24T09:24:54 Z	hongjun7	Σ (kriii4_P2)	C++	100 / 100	16 ms	1240 KB

P2

#include <stdio.h>
int mod = 1e9 + 7;
long long f(long long a, long long b) {
	if (b == 0) return 1;
	if (b == 1) return a;
	long long v = f(a, b / 2);
	v = (v*v) % mod;
	if (b & 1) v = (v*a) % mod;
	return v;
}
long long mul(long long a, long long b) {
	return (a*b) % mod;
}
long long div(long long a, long long b) {
	return (a * f(b, mod - 2)) % mod;
}
long long a[10005], b[10005];
int main() {
	int m;
	long long N = 1, X = 0;
	scanf("%d", &m);
	for (int i = 1; i <= m; i++) {
		scanf("%lld%lld", &b[i], &a[i]);
		N = mul(N, b[i]);
	}
	for (int i = 1; i <= m; i++) {
		long long g = div(N, b[i]);
		long long v = mul(a[i], g);
		X = (X + v) % mod;
	}
	X = div(X, N);
	printf("%lld", X);
}

Subtask #1

100.0 / 100.0

#	결과	실행 시간	메모리	Grader output
1	Correct	15 ms	1240 KB	Output is correct
2	Correct	15 ms	1240 KB	Output is correct
3	Correct	15 ms	1240 KB	Output is correct
4	Correct	15 ms	1240 KB	Output is correct
5	Correct	15 ms	1240 KB	Output is correct
6	Correct	16 ms	1240 KB	Output is correct
7	Correct	15 ms	1240 KB	Output is correct
8	Correct	11 ms	1240 KB	Output is correct
9	Correct	11 ms	1240 KB	Output is correct
10	Correct	16 ms	1240 KB	Output is correct
11	Correct	15 ms	1240 KB	Output is correct
12	Correct	14 ms	1240 KB	Output is correct
13	Correct	9 ms	1240 KB	Output is correct
14	Correct	11 ms	1240 KB	Output is correct
15	Correct	14 ms	1240 KB	Output is correct
16	Correct	11 ms	1240 KB	Output is correct
17	Correct	11 ms	1240 KB	Output is correct
18	Correct	14 ms	1240 KB	Output is correct
19	Correct	15 ms	1240 KB	Output is correct
20	Correct	14 ms	1240 KB	Output is correct