题解 | #扭蛋机#java二叉树

import java.util.Scanner;
import java.util.*;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int traget = in.nextInt();
        //假设这是二叉树
        //如果结果为奇数，则走左边，反之走右边
        List<Character> path = new ArrayList<>();
        while(traget > 0){
            if(traget % 2 == 0){
                //为偶数的话证明是走二叉树右边，意味着2*x + 2了
                path.add('3');
                traget = (traget - 2) / 2;
            }else{
                //奇数的话走了左边
                path.add('2');
                traget = (traget - 1) / 2;
            }
        }
        Collections.reverse(path);
        StringBuilder sb = new StringBuilder();
        for(int i = 0;i<path.size();i++){
            sb.append(path.get(i));
        }
        System.out.print(sb);
    }

}