Dice (III)（掷骰子&每面至少出现1次的期望）

#include <algorithm>
#include <bitset>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <deque>
#include <functional>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <vector>
//#include <unordered_map>
//#include <unordered_set>
//#include <bits/stdc++.h>
//#define int long long
#define pb push_back
#define PII pair<int, int>
#define mpr make_pair
#define ms(a, b) memset((a), (b), sizeof(a))
#define x first
#define y second
typedef long long ll;
const int inf = 0x3f3f3f3f;
const ll INF = 0x3f3f3f3f3f3f3f3f;
const int N = 1e6 + 7;
using namespace std;

int main(int argc, char const *argv[]) {
    int T;
    int Case = 0;
    scanf("%d", &T);
    while (T--) {
        int n;
        scanf("%d", &n);
        double s=0;
        for(int i=1;i<=n;i++){
            s+=n*1.0/i;
        }
        printf("Case %d: ",++Case);
        printf("%.10lf\n",s);
    }
    return 0;
}