LightOJ 1245 Harmonic Number (II) 水题

#include <cstdio>
#include <iostream>
#include <ctime>
#include <vector>
#include <cmath>
#include <map>
#include <queue>
#include <algorithm>
#include <cstring>
using namespace std;
typedef long long LL;
const int N=5e4+5;
const int INF=0x3f3f3f3f;
int main()
{
    int cas=0,T;
    scanf("%d",&T);
    while(T--){
      LL n;
      scanf("%lld",&n);
      LL ans=n;
      for(LL i=2;i<=n;++i){
        LL tmp=n/i;
        LL pos=n/tmp;
        ans=ans+(pos-i+1)*tmp;
        i=pos;
      }
      printf("Case %d: %lld\n",++cas,ans);
    }
    return 0;
}