题解 | #求int型正整数在内存中存储时1的个数#

利用Integer的方法转换为二进制，然后字符串处理即可

import java.util.*;

public class Main {

    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        String string = Integer.toBinaryString(s.nextInt());
        System.out.println(string.length() - string.replace("1","").length());
    }
}