Submission #20075

#	Time	Username	Problem	Language	Result	Execution time	Memory
20075		gs13068	로봇 (kriii4_F)	C++98	4 / 100	40 ms	524288 KiB

F

#include <cstdio>
#include <map>

const int p = 1000000007;

using namespace std;

int f(int x, int y)
{
	return y & 1 ? (long long)f(x, y ^ 1)*x%p : y ? f((long long)x*x%p, y >> 1) : 1;
}

map<pair<int, pair<pair<int, int>, int> >, int> MM;

int px[4] = { 1,0,-1,0 };
int py[4] = { 0,1,0,-1 };

int L, R, M;

int g(int n, int x, int y, int z)
{
	if (n == 0) return x*x + y*y;
	if (MM.find(make_pair(n, make_pair(make_pair(x, y), z))) != MM.end()) return MM[make_pair(n, make_pair(make_pair(x, y), z))];
	int a = (long long)g(n - 1, x + px[z], y + py[z], z) * M % p;
	z = z + 1 & 3;
	int b = (long long)g(n - 1, x + px[z], y + py[z], z) * L % p;
	z = z + 2 & 3;
	int c = (long long)g(n - 1, x + px[z], y + py[z], z) * R % p;
	return MM[make_pair(n, make_pair(make_pair(x, y), z + 1 & 3))] = ((long long)a + b + c) * f(L + R + M, p - 2) % p;
}

int main()
{
	int n;
	scanf("%d%d%d%d", &n, &L, &M, &R);
	printf("%d", g(n, 0, 0, 0));
}

• Subtask 1: 4 / 4
• Subtask 2: 0 / 96