[코테5] 특정 문자 뒤집기

import java.util.*;

class Main{
  public static char[] solution(String input){
   char[] in_char =  input.toCharArray();
    for(int i=0;i<input.length();i++){
         char x =input.charAt(i);
         if((x>=65&&x<=90) ||(x>=97&&x<=122) )
             in_char[input.length()-i]=x;
         else in_char[i]=x;
    }
   return in_char;

  }
  public static void main(String[] args){
    Scanner kb = new Scanner(System.in);
    String input = kb.next();
    System.out.println(solution(input));

  }
}

in_char[input.length()-i-1]=x;

import java.util.*;

class Main{
  public static char[] solution(String input){
   char[] in_arr = new char[input.length()];
    for(int i=0;i<input.length();i++){
         char x =input.charAt(i);
         if( !(x>=65&&x<=90) && !(x>=97&&x<=122) ){
                      in_arr[i]=x;
         }
        
    }
    
    for(int i=0;i<input.length();i++){
         char y =input.charAt(i);
         if( (y>=65&&y<=90) || (y>=97&&y<=122)) {
           for(int j=input.length()-1;j>=0;j--){
               if(in_arr[j]==0){
                  in_arr[j]=y;
                   break;
         }
        }//for j
     } //if
   }//for i

   return in_arr;

  }
  public static void main(String[] args){
    Scanner kb = new Scanner(System.in);
    String input = kb.next();
    System.out.println(solution(input));

  }
}

✔ 강의 답

import java.util.*;

public class Main{

  public static String solution(String input){
    String answer;
    char[] s = input.toCharArray();
    int lt=0, rt=s.length-1;
    while(lt<rt) {
    	if(!Character.isAlphabetic(s[lt])) lt++;
    	else if(!Character.isAlphabetic(s[rt])) rt--;
    	else {
    		char tmp = s[lt];
    		s[lt]=s[rt];
    		s[rt]= tmp;
    		rt--;
    		lt++;
    	}
    }
	  
	  answer = String.valueOf(s);
	  return answer;
	  
 }
 
  public static void main(String[] args){
    Scanner kb = new Scanner(System.in);
    String input = kb.next();
    System.out.println(solution(input));

  }
 
}