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;
}
}
.