SPOJ Favorite Dice（期望DP入门）

https://vjudge.net/problem/SPOJ-FAVDICE

https://blog.csdn.net/myjs999/article/details/81022546

#define IO std::ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);
#define bug(x) cout<<#x<<" is "<<x<<endl
#include <bits/stdc++.h>
#define iter ::iterator
using namespace  std;
typedef long long ll;
typedef pair<int,ll>P;
#define pb push_back
#define mk make_pair
#define se second
#define fi first
#define rs o*2+1
#define ls o*2
const ll inf=1e18;

const int N=1e5+5;

int T;

int n,m;
 
double d[N];

int main(){

    IO;
    cin>>T;
    cout.precision(2);
    cout.setf(ios::fixed);
    while(T--){
        cin>>n;
        d[n]=0;
        for(int i=n-1;i>=0;i--){
            d[i]=(double)n/(n-i)+d[i+1];
        }
        
        cout<<d[0]<<endl;
    }



}