UVA 10791 -唯一分解定理的应用

#include<iostream>
#include<stdio.h>
#include<algorithm>
#include<string.h>
#include<math.h>
#define ll long long
using namespace std;
int main(){
  int n;
  int k=0;
  while(1){
     k++;
     scanf("%d",&n);
    if (n==0)break;
    int m=sqrt(n+1);
    int cnt=0;
    ll ans=0;
    for (int i=2;i<=m;i++){
        if (n%i==0){
            ll num=1;
            cnt++;
            while(n%i==0){
                num*=i;
                n/=i;
            }
           ans+=num;
        }
        if (n==1)break;
    }
    if (n!=1 || cnt==0){
        ans+=n;
        cnt++;
    }
    if (cnt==1){
        ans++;
    }
    printf("Case %d: %lld\n",k,ans);

  }
  return 0;
}