Submission #3780171

---

Source Code Expand

#include <bits/stdc++.h>
using namespace std;
long long int D;
int N;
double memo[101][75][40][20];
double P(int i,int a,int b,int c){
    if(memo[i][a][b][c] != -1) return memo[i][a][b][c];
    double ans=0;
    if(i == 1){
        for(int j=1;j<=6;j++){
            if(j % (int)(pow(2,a)*pow(3,b)*pow(5,c)) == 0) ans++;
        }
        return memo[1][a][b][c] = ans;
    }
    if(memo[i][a][b][c] != -1) return memo[i][a][b][c];
    ans = P(i-1,a,b,c) + P(i-1,max(a-1,0),b,c) + P(i-1,a,max(b-1,0),c) + P(i-1,max(a-2,0),b,c) + P(i-1,a,b,max(c-1,0)) + P(i-1,max(a-1,0),max(b-1,0),c);
    return memo[i][a][b][c] = ans;
}

int main(){
    for(int q=0;q<101;q++){
        for(int w=0;w<75;w++){
            for(int e=0;e<40;e++){
                for(int r=0;r<20;r++) memo[q][w][e][r] = -1;
            }
        }
    }
    cin >> N >> D;
    int a=0;
    int b=0;
    int c=0;
    while(D%2 == 0){
        D = D/2;
        a++;
    }
    while(D%3 == 0){
        D = D/3;
        b++;
    }
    while(D%5 == 0){
        D = D/5;
        c++;
    }
    if(D != 1) cout << 0 << endl;
    else{
        double ans = P(N,a,b,c) / 6;
        for(int i=0;i<N-1;i++){
            ans = ans/6;
        }
        cout << setprecision(8) << ans << endl;
    }
    return 0;
}

Submission Info

Judge Result