Submission #38947181

---

Source Code Expand

#include <bits/stdc++.h>

using namespace std;
using i64 = long long;
const int mod = 998244353;
const int N = 1e5 + 10;
#define endl '\n'
using db = double;

void solve()
{
    int n;
    cin >> n;
    vector<vector<db>> dp(n + 1, vector<db>(n + 1));
    vector<db> p(n + 1);
    for(int i = 1; i <= n; i++){
        cin >> p[i];
    }
    dp[0][0] = 1;
    for(int i = 1; i <= n ; i++){
        dp[i][0] = dp[i - 1][0] * (1 - p[i]);
        for(int j = 1; j <= i; j++){
            dp[i][j] = dp[i - 1][j - 1] * p[i] + dp[i - 1][j] * (1 - p[i]);
        }
    }
    db res = 0;
    for(int i = n / 2 + 1; i <= n; i++)
        res += dp[n][i];
    cout << setprecision(10) << res << endl;
}
int main()
{
#ifdef ONLINE_JUDGE
    ios::sync_with_stdio(false);
    cin.tie(nullptr), cout.tie(nullptr);
#endif
    int _ = 1;
    //cin >> _;
    while (_--)
        solve();
}

Submission Info

Judge Result