题解 | #求int型正整数在内存中存储时1的个数#

 
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int num = sc.nextInt();
        String str = Integer.toBinaryString(num);
        int count = 0;
        for(int i = 0; i < str.length(); i++) {
            if(str.charAt(i) == '1')
                count++;
        }
        System.out.println(count);
    }
}