选择题

自连接使用一张表

编程题
题目1

import java.util.Scanner;

public class Main { 	
	public static int res(int n) {
		StringBuffer s = new StringBuffer();
		while(n!=0) {
			s.append(n%2);
			n/=2;
		}
		int sum = 0;
		String ss = s.reverse().toString();
		for(int i=0;i<ss.length();i++) {
			if(s.charAt(i) == '1')
				sum++;
		}
		return sum;
	}
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		while(sc.hasNext()) {
			int n = sc.nextInt();
			System.out.println(res(n));
		}
		sc.close();
	}
}