JAVA朴素解法-多类型

import java.util.*;
public class Main{
    public static void main(String[] args){
        Scanner in=new Scanner(System.in);
        int a=in.nextInt();
        System.out.println(getString3(a));//
        //getString1(a);
    }
    public static  String getString(int a){
        StringBuilder res=new StringBuilder();
        while(a!=0){
            res.append(String.valueOf(a%10));
            a=a/10;
        }
        return res.toString();
    }
    public static  String getString0(int a){
        StringBuffer res=new StringBuffer(a);
        res.reverse();
        return res.toString();
    }
    public static  void getString1(int a){
        String str = Integer.toString(a);//int -> String 的三个方法都ok
        char[] chararr = str.toCharArray();
        for(int i=0;i<chararr.length;i++){
            System.out.print(chararr[chararr.length-1-i]);
        }
        return ;
    }
    public static  String getString2(int a){
        String str = Integer.toString(a);//int -> String 的三个方法都ok
        char[] chararr = str.toCharArray();
        for(int i=0;i<chararr.length/2;i++){
            char tmp=chararr[i];
            chararr[i]=chararr[chararr.length-1-i];
            chararr[chararr.length-1-i]=tmp;
        }
        return new String(chararr);
    }
    public static  String getString3(int a){
        String str = Integer.toString(a);//int -> String 的三个方法都ok
        char[] chararr = str.toCharArray();
        StringBuilder res=new StringBuilder();
        for(int i=0;i<chararr.length;i++){
            res.append(String.valueOf(chararr[chararr.length-1-i]));

        }
        return res.toString();
    }
}