Submission #3015012

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Source Code Expand

#include <iostream>
#include <iomanip>
#include <cstring>

using ll = long long;
using namespace std;
double dp[2][80][60][40];

int main() {
    int n;
    int l[3] = {2,3,5};
    int ld[3] = {};
    ll d;
    cin >> n >> d;
    for (int i = 0; i < 3; ++i) {
        while (d % l[i] == 0){
            d /= l[i];
            ld[i]++;
        }
    }
    if(d > 1){
        cout << setprecision(12) << 0.0 << "\n";
    }
    fill_n(&dp[0][0][0][0], 384000, 0.0);
    dp[0][0][0][0] = 1.0f;

    for (int i = 0; i <= n; ++i) {
        int a = i % 2;
        int b = 1^a;
        fill_n(&dp[b][0][0][0], 192000, 0);
        for (int j = 0; j < 80; ++j) {
            for (int k = 0; k < 60; ++k) {
                for (int m = 0; m < 40; ++m) {
                    if(dp[a][j][k][m] == 0.0) continue;
                    dp[b][j][k][m] += (dp[a][j][k][m]/6.0);
                    dp[b][j+1][k][m] += (dp[a][j][k][m]/6.0);
                    dp[b][j][k+1][m] += (dp[a][j][k][m]/6.0);
                    dp[b][j+2][k][m] += (dp[a][j][k][m]/6.0);
                    dp[b][j][k][m+1] += (dp[a][j][k][m]/6.0);
                    dp[b][j+1][k+1][m] += (dp[a][j][k][m]/6.0);
                }
            }
        }
    }
    double ans = 0.0;
    for (int i = ld[0]; i < 80; ++i) {
        for (int j = ld[1]; j < 60; ++j) {
            for (int k = ld[2]; k < 40; ++k) {
                ans += dp[n%2][i][j][k];
            }
        }
    }

    cout << setprecision(14) << ans << "\n";
    return 0;
}

Submission Info

Judge Result