Submission #20012

#	Time	Username	Problem	Language	Result	Execution time	Memory
20012		algoshipda	창문 (kriii4_C)	C++14	3 / 100	0 ms	1720 KiB

C

#include <bits/stdc++.h>
using namespace std;

typedef long long lld;
const lld MOD = 1e9 + 7;

inline void norm(lld& a)
{
	a = ((a % MOD + MOD) % MOD);
}

inline lld norm2(lld a)
{
	return a = ((a % MOD + MOD) % MOD);
}
inline void mult(lld& a, lld b)
{
	norm(a);
	norm(b);
	a = 1ll * a * b;
	norm(a);
}

inline lld mult2(lld a, lld b)
{
	
	norm(a);
	norm(b);
	return norm2(1ll * a * b);
}

pair<lld, lld> extgcd(lld a, lld b)
{
	if(b == 0) return {1,0};
	pair<lld, lld> t = extgcd(b, a%b);
	return {t.second, t.first - t.second*(a/b)};
}

lld inv(lld a)
{
	return norm2(extgcd(a, MOD).first);
}

int main()
{
	lld h, w;
	scanf("%lld%lld",&h,&w);
	h %= MOD;
	w %= MOD;
	lld b = mult2(mult2(mult2(h,(h+1)%MOD), mult2(w,(w+1)%MOD)), inv(4));
	lld hh = h;
	mult(hh, (h+1)%MOD);
	mult(hh, (h+2)%MOD);
	mult(hh, inv(6));
	lld ww = w;
	mult(ww, (w+1)%MOD);
	mult(ww, (w+2)%MOD);
	mult(ww, inv(6));
	lld a = mult2(hh,ww);
	mult(a, 9);
	printf("%lld",mult2(a, inv(b)));
}

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