UVA 557 Burger——概率

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
const int maxn = 1e5+10;
int n;
double p[maxn];
void init(){
    p[1] = 1.0;
    for(int i = 1 ; i < maxn ; i++) {
        p[i+1] = (1-0.5/i)*p[i];
    }
}
int main() {
    init();
    int T;
    scanf("%d", &T);
    while (T--) {
        scanf("%d", &n);
        printf("%.4lf\n", 1-p[n/2]);
    }
}