CF 579A (二进制拆分)

在培养皿中，每个细胞每天会繁殖，数量*2
我们可以在任意天加入任意数量的细胞入培养皿中。
想要知道最少加入多少个细胞，可以使得有一天，培养皿中细胞的数量会恰好为x

其实就是输出X的二进制中有多少个1

Sample test(s)
input
5
output
2
input
8
output
1

 # include <iostream>
 # include <cstdio>
 # include <cstring>
 # include <algorithm>
 # include <string>
 # include <cmath>
 # include <queue>
 # include <list>
 # define LL long long
 using namespace std ;

 int main()
 {
     //freopen("in.txt","r",stdin) ;
     int n ;
     while(scanf("%d",&n) != EOF)
     {
         int sum =  ;
         while(n)
         {
             if (n & )
                 sum++ ;
             n >>=  ;
         }
         printf("%d\n" , sum) ;
     }

     return ;
 }