Submission #3780138

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Source Code Expand

#include<iostream>
#include<string>
#include<cmath>
#include<queue>
#include<map>
#include<set>
#include<list>
#include<iomanip>
#include<vector>
#include<random>
#include<functional>
#include<algorithm>
#include<stack>
#include<cstdio>
#include<bitset>
#include<unordered_map>
#include <climits>
#include<fstream>
using namespace std;
//---------------------------------------------------
//ライブラリゾーン！！！！
typedef long long ll;
typedef long double ld;
#define str string
#define rep(i,j) for(ll i=0;i<(long long)(j);i++)
#define all(a) (a).begin(),(a).end()
const ll Mod = 1000000007;
const ll gosenchou = 5000000000000000;
short gh[2][4] = { { 0,0,-1,1 },{ -1,1,0,0 } };
struct P {
	ll pos, cost;
};
bool operator<(P a, P b) { return a.cost < b.cost; }
bool operator>(P a, P b) { return a.cost > b.cost; }
struct B {//隣接リスト表現
	ll to, cost;
};
struct E {//辺の情報を入れる変数
	ll from, to, cost;
};
bool operator<(E a, E b) {
	return a.cost < b.cost;
}
struct H {
	ll x, y;
};
bool operator<(H a, H b) {
	if (a.x != b.x) return a.x < b.x;
	return a.y < b.y;
}
bool operator>(H a, H b) {
	if (a.x != b.x) return a.x > b.x;
	return a.y > b.y;
}
bool operator==(H a, H b) {
	return a.x == b.x&&a.y == b.y;
}
bool operator!=(H a, H b) {
	return a.x != b.x || a.y != b.y;
}
struct LS {
	ll num, cost;
	//値、遅延配列
};
ll gcm(ll i, ll j) {//最大公約数
	if (i > j) swap(i, j);
	if (i == 0) return j;
	return gcm(j%i, i);
}
ld rad(H a, H b) {
	return sqrt(pow(a.x - b.x, 2.0) + pow(a.y - b.y, 2.0));
}//rad＝座標上の2点間の距離
ll ari(ll a, ll b, ll c) {
	return (a + b)*c / 2;
}//等差数列の和
ll fact(ll x, ll k, ll p) {//最大値、個数、あまり
	ll sum = 1;
	for (int i = 0; i < k; i++) {
		sum *= (x--);
		sum %= p;
	}
	return sum;
}//階乗(正）
ll mod_pow(ll x, ll n, ll p) {
	ll res = 1;
	while (n > 0) {
		if (n & 1) res = res * x%p;
		x = x * x%p;
		n >>= 1;
	}
	return res;
}//x^n%p
short ctos(char a) {
	return (int)(a - '0');
}
const ll Inf = 4523372036854775807;
const int inf = 1500000000;
#define int long long
//----------------------------------------------------
//++++++++++++++++++++++++++++++++++++++++++++++++++++
int n, d;
ld dp[100][60][60][60];
//i, two, tre, five
int two, tre, five;
signed main() {
	cin >> n >> d;
	while (d % 2 == 0) {
		two++;
		d /= 2;
	}
	while (d % 3 == 0) {
		tre++;
		d /= 3;
	}
	while (d % 5 == 0) {
		five++;
		d /= 5;
	}
	if (d != 1) {
		cout << 0 << endl;
		return 0;
	}
	dp[0][0][0][0] = 1;
	//2^0 * 3^0 * 5^0
	for (int i = 0; i < n; i++) {
		for (int x = 0; x <= two; x++) {
			for (int y = 0; y <= tre; y++) {
				for (int z = 0; z <= five; z++) {
					dp[i + 1][x][y][z] += dp[i][x][y][z] / 6;
					dp[i + 1][min(two, x + 1)][y][z] += dp[i][x][y][z] / 6;
					dp[i + 1][x][min(tre, y + 1)][z] += dp[i][x][y][z] / 6;
					dp[i + 1][x][y][min(five, z + 1)] += dp[i][x][y][z] / 6;
					dp[i + 1][min(two, x + 2)][y][z] += dp[i][x][y][z] / 6;
					dp[i + 1][min(two, x + 1)][min(tre, y + 1)][z] += dp[i][x][y][z] / 6;
				}
			}
		}
	}
	ld ans = dp[n][two][tre][five];
	printf("%.11LF\n", ans);
}

Submission Info

Judge Result