1 #include <algorithm> 2 #include <iostream> 3 #include <cstring> 4 #include <cstdlib> 5 #include <cstdio> 6 #include <vector> 7 #include <ctime> 8 #include <queue> 9 #include <list>10 #include <set>11 #include <map>12 using namespace std;13 #define INF 0x3f3f3f3f14 typedef long long LL;15 16 double dp[100010];17 double solve(int n)18 {19     if(dp[n] != -1)20         return dp[n];21     double res = 0;22     double con = 2;23     for(int i = 2; i * i <= n; i++)24     {25         if(n % i != 0)26             continue;27         con++;28         res += solve(i);29         if(i * i != n){30             res += solve(n / i);31             con++;32         }33     }34     res += con;35     res /= con-1;36     dp[n] = res;37     return res;38 }39 int main()40 {41     int t, n;42     scanf("%d", &t);43     for(int i = 1; i < 100001; i++)44         dp[i] = -1;45     dp[1] = 0;46     for(int ca = 1; ca <= t; ca++)47     {48         scanf("%d", &n);49         printf("Case %d: %.6f\n", ca, solve(n));50     }51     return 0;52 }