题解 |HJ62 #查找输入整数二进制中1的个数#

import java.util.*;

// 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 scanner = new Scanner(System.in);
        while (scanner.hasNextInt()) {
            int i = scanner.nextInt();
            double v = Math.pow(2, 31) - 1;
//        2567237
            if (1 <= i && i <= v) {
                String str = Integer.toBinaryString(i);
                char[] chars = str.toCharArray();
                int num = 0;
                for (char ch : chars) {
                    if (ch == '1') {
                        num++;
                    }
                }
                System.out.println(num);
            }
        }
    }
}