牛客网编程练习之京东2017校招题：幸运数

不需要思路，简单的模拟就可以AC....

AC代码：

import java.util.Scanner;

/**
* @author CC11001100
*/
public class Main {

public static void main(String[] args) {

Scanner sc = new Scanner(System.in);
int n = sc.nextInt();
int ans = 0;
for(int i=1; i<=n; i++){
ans += f(i) == g(i) ? 1 : 0;
}
System.out.println(ans);

}

private static int f(int n){
int res = 0;
while(n>0){
res+=n%10;
n/=10;
}
return res;
}

private static int g(int n){
int res = 0;
while(n>0){
res+= n & 0X1;
n>>=1;
}
return res;
}

}

题目来源： https://www.nowcoder.com/practice/4d1afe11171c44a385287e29092cdb3f?tpId=85&tqId=29881&tPage=1&rp=1&ru=/ta/2017test&qru=/ta/2017test/question-ranking

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