Submission #19785

#	Time	Username	Problem	Language	Result	Execution time	Memory
19785		hongjun7	창문 (kriii4_C)	C++98	3 / 100	0 ms	1084 KiB

C

#include <stdio.h>
const 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) {
	a %= mod; b %= mod;
	if (a < 0) a += mod;
	if (b < 0) b += mod;
	return (a*b) % mod;
}
long long div(long long a, long long b) {
	return (a * f(b, mod - 2)) % mod;
}
long long n, m;
long long p1, q, p2, p3, p4, p, v;
int main() {
	scanf("%lld%lld", &n, &m); n %= mod; m %= mod;
	q = mul(mul(mul(n, n + 1), m), m + 1);
	p1 = mul(mul(mul(mul(mul(mul(9, m), m + 1), n), n + 1), n + 1), m + 1);
	p2 = mul(mul(mul(mul(mul(mul(3, m), m + 1), n), n + 1), 2 * n + 1), -1 - m);
	p3 = mul(mul(mul(mul(mul(m, m + 1), 2 * m + 1), n), n + 1), 2 * n + 1);
	p4 = mul(mul(mul(mul(mul(mul(3, m), m + 1), 2 * m + 1), n), n + 1), -n - 1);
	if (p1 < 0) p1 += mod;
	if (p2 < 0) p2 += mod;
	if (p3 < 0) p3 += mod;
	if (p4 < 0) p4 += mod;
	p = (p1 + p2 + p3 + p4) % mod;
	printf("%lld", div(p, q));
}

• Subtask 1: 3 / 3
• Subtask 2: 0 / 97