题解 | #求int型正整数在内存中存储时1的个数#

import java.util.*;
public class Main {
    public static void main(String args[]) {
        Scanner sc = new Scanner(System.in);
        while (sc.hasNextInt()) {
            int n = sc.nextInt();
            String s = trans(n, 2);
            int yi = 0;
            
            for (int i = 0; i < s.length(); i++) {

                if (s.charAt(i) == '1') {
                    yi++;
                }
               
            }
             System.out.println(yi);
        }
    }
    public static String trans(int num, int radix)
  {
    if(radix == 2)
      return Integer.toBinaryString(num);
    else if(radix == 8)
      return Integer.toOctalString(num);
    else if(radix == 16)
      return Integer.toHexString(num);
 
    return null;
  }
}