题解 | #求int型正整数在内存中存储时1的个数#

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int in = sc.nextInt();
        int count = 0;
        while (in > 0) {
            if (in % 2 == 1) {
                count ++;
            }
            in = in / 2;
        }

        System.out.println(count);
    }
}