题解 | #查找输入整数二进制中1的个数#

import java.util.InputMismatchException;

import java.util.Scanner;
import java.util.Stack;


public class Main {


	public static void main(String[] args) {
		
		Scanner scanner = new Scanner(System.in);
		
		int dec;//保存输入的十进制数值
		Stack<Integer> stack = new Stack<>();
		int a;//保存余数
		
		try{
			
			while(true){
				if(scanner.hasNextInt()){
					dec = scanner.nextInt();
					while(dec != 0){
						a = dec % 2;//取余数
						dec = dec / 2;//把被除数变成模运算后的商，继续下一轮取余运算
						stack.push(a);//余数入栈
					}
					
					int count = 0;//用来计算1的个数
					
					while(!stack.isEmpty()){
						Integer b = stack.pop();
						if(b.equals(1)){
							count++;
						}
					}
					System.out.println(count);//输出1的个数
				}else break;
			}
			
			
		}catch (InputMismatchException e){
			
			System.out.println("请输入1个十进制整数！");
		}
		
		scanner.close();
	}

}