「算法」水仙花 java_网易

import java.util.Scanner;

public class Main{

private static String magic(int n,String res){
while(n>0){
if(n%2==0){
res ='2' + res;
n=(n-2)/2;
}
else{
res ='1' + res;
n=(n-1)/2;
}
}
return res;
}
public static void main(String [] args){
Scanner sc = new Scanner(System.in);
int a = sc.nextInt();
String res = "";
System.out.print(magic(a, res));
}
}