一个数可以用二进制表示，也可以用十进制表示，如果该数的二进制表示法所有位数字之和等于十进制表示法所有位数之和，则称该数为神奇数，求小于等于M的神奇数有多少

[code]import java.util.LinkedList;
import java.util.Scanner;
import java.util.Stack;

public class suanFa01 {
public static void main(String[] args) {
Stack<Integer> stack = new Stack<Integer>();
LinkedList list = new LinkedList();
Scanner console = new Scanner(System.in);
int M = console.nextInt();
int sum1 = 0;
int sum2 = 0;
Find(M,stack,sum1,list,sum2);
}
public static void Find(int M,Stack<Integer> stack,int sum1,LinkedList list,int sum2){
for(int i = 1; i <= M; i ++){
int temp = i;
while(i != 0){
int x = i % 2;
i /= 2;
stack.push(x);
}
while(stack.size() > 0){
int y = stack.pop();
sum1 += y;
}
i = temp;
while(i != 0){
int z = i % 10;
i /= 10;
sum2 += z;
}
if(sum1 == sum2){
list.add(temp);
}
i = temp;
sum1 = 0;
sum2 = 0;
}
System.out.println(list.size());
System.out.println(list);
}
}

[code]100
3
[1, 20, 21]