题解 | 牛牛逆序输出

using System;
using System.Text;
public class Program {
    public static void RePrint(StringBuilder s,int n){
        if(n==0){
            return;
        }
        int a=n%10;
        s.Append(a);
        RePrint(s,n/10);
    }
    public static void Main() {
        int n=int.Parse(Console.ReadLine());
        StringBuilder s=new StringBuilder();
        RePrint(s,n);
        int res=int.Parse(s.ToString());
        Console.WriteLine(res);
    }
}