uva 11762

<pre name="code" class="cpp">#include <bits/stdc++.h>using namespace std;#define maxn 1000000+10bool isprime[maxn];int  mark[maxn];double dp[maxn];int T, n;void make_prime(int num){    int tmp=sqrt(num+0.5);    memset(isprime,true,sizeof(isprime));    for(int i=2; i<=tmp; i++)        if(isprime[i])            for(int j=i*i; j<=num; j+=i)                isprime[j]=false;    isprime[0] = false;    isprime[1] = false;    int cnt = 0;    for(int i=2; i<=num; i++)        if(isprime[i]) mark[i] = ++cnt;        else mark[i] = cnt;}double solve(int m){    int k = 0;    if(m == 1) return 0;    if(dp[m]) return dp[m];    for(int i=2; i<=m; i++)        if(isprime[i] && m%i == 0)            {                dp[m] += solve(m/i)/mark[m];                k++;            }    dp[m] += mark[m]/(double)k;    return dp[m];}int main(){    freopen("input.txt", "r", stdin);    freopen("output.txt", "w", stdout);    cin>>T;    make_prime(maxn);    while(T--)    {        memset(dp, 0, sizeof(dp));        cin>>n;        double ans = solve(n);        printf("%.10lf\n", ans);    }    return 0;}