[코테8] 유효한 팰린드롬

✔ 내 답 -> 맞음

import java.util.*;

public class Main {
  public static String solution(String input) {
	  String s = "";
             input=input.replace(" ","");
            // System.out.println(input);
	  for(int i=0;i<input.length();i++) {
		  if(Character.isAlphabetic(input.charAt(i))) {
			  s+=String.valueOf(input.charAt(i));
		  }
	  }
              //System.out.println("이상한 문자 제거"+s);
	  s=s.toUpperCase();
	  char[] sarr =s.toCharArray();
	  int lt =0, rt=sarr.length-1;
	   while(lt<rt){
		   char tmp = sarr[lt];
		   sarr[lt]=sarr[rt];
		   sarr[rt]=tmp;
		   lt++;
		   rt--;  
	   }  
	   String s_rev=String.valueOf(sarr);
	   if(s.equals(s_rev)) return "YES";
	   else return "NO";
	    
  }
  public static void main(String[] args) {
	  Scanner kb = new Scanner(System.in);
	  String input = kb.nextLine();
	  System.out.println(solution(input));
	   
  }  
	
}

✔️ 강의 답

import java.util.*;

public class Pro8 {
  public static String solution(String input) {
	  String answer ="NO";
	  input=input.toUpperCase().replaceAll("[^A~Z]","");
	  String tmp = new StringBuilder(input).reverse().toString();
	  if(input.equals(tmp)) answer="YES";
	  return answer;
  }
  public static void main(String[] args) {
	  Scanner kb = new Scanner(System.in);
	  String input = kb.next();
	  System.out.println(solution(input));
	  
	  
	  
  }
	
	
	
}