Race to 1 Again LightOJ
阿新 • • 發佈:2018-12-20
Rimi learned a new thing about integers, which is - any positive integer greater than 1 can be divided by its divisors. So, he is now playing with this property. He selects a number N. And he calls this D.
In each turn he randomly chooses a divisor of D (1 to D). Then he divides D by the number to obtain new D
Input
Input starts with an integer T (≤ 10000), denoting the number of test cases.
Each case begins with an integer N (1 ≤ N ≤ 105).
Output
For each case of input you have to print the case number and the expected value. Errors less than 10-6 will be ignored.
Sample Input
3
1
2
50
Sample Output
Case 1: 0
Case 2: 2.00
Case 3: 3.0333333333
#include<bits/stdc++.h> #define ll long long using namespace std; double dp[100010]; void init() { dp[1]=0; for(int i=2;i<=100000;i++) { int cnt=0; double ans=0.0; for(int j=1;j*j<=i;j++) { if(i%j==0) { cnt++; ans+=dp[j]; if(i/j!=j) { cnt++; ans+=dp[i/j]; } } } dp[i]=(ans/(cnt-1))+((cnt)*1.0/(cnt-1)); } } int main() { init(); int t,n; scanf("%d",&t); for(int oo=1;oo<=t;oo++) { scanf("%d",&n); printf("Case %d: %lf\n",oo,dp[n]); } }