题解 | #查找输入整数二进制中1的个数#

public class Main {
     public static void main(String[] args){
         Scanner sc = new Scanner(System.in);
         while (sc.hasNext()) {
            int num= sc.nextInt();
            //把数字转成二进制
            String s = Integer.toBinaryString(num);
            int cnt = 0;
            //字符串转数组
            char[] chars = s.toCharArray();
            //对chars进行循环
            for (char aChar : chars) {
                if (aChar=='1'){
                    cnt++;
                }
            }
            System.out.println(cnt);
        }
     }
}