Codeforces Round #320 (Div. 2)(A)

A. Raising Bacteria
time limit per test 1 second
memory limit per test 256 megabytes
inputstandard input
outputstandard output

You are a lover of bacteria. You want to raise some bacteria in a box.

Initially, the box is empty. Each morning, you can put any number of bacteria into the box. And each night, every >bacterium in the box will split into two bacteria. You hope to see exactly x bacteria in the box at some moment.

What is the minimum number of bacteria you need to put into the box across those days?

Input
The only line containing one integer x (1 ≤ x ≤ 109).

Output
The only line containing one integer: the answer.

Sample test(s)
input
5
output
2
input
8
output
1
Note
For the first sample, we can add one bacterium in the box in the first day morning and at the third morning there >will be 4 bacteria in the box. Now we put one more resulting 5 in the box. We added 2 bacteria in the process so the >answer is 2.

For the second sample, we can put one in the first morning and in the 4-th morning there will be 8 in the box. So the >answer is 1.

简单模拟题，求一个数二进制中一的个数

#include<iostream>using namespace std;int main(void){    int x;    while(cin >> x)    {        int ans = 0;        while(x)        {            if(x&1) ans++;            x >>= 1;        }        cout << ans << endl;    }    return 0;}