[LeetCode] 9. Palindrome Number

leetcode.com/problems/palindrome-number/

Palindrome Number - LeetCode

 

1. Problem

Determine whether an integer is a palindrome. An integer is a palindrome when it reads the same backward as forward.

Follow up: Could you solve it without converting the integer to a string?

 

2.Code

public class PalindromeNumber {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		
		boolean result = isPalindrome(121);
	}
	
    public static boolean isPalindrome(int x) {
        
    	String beforeString = Integer.toString(x);
    	StringBuffer afterString = new StringBuffer();
    	
    	for(int i = beforeString.length()-1; i >= 0 ; i--) {
    		afterString.append(beforeString.charAt(i));
    	}
    	
    	if(beforeString.equals(afterString.toString())) {
    		return true;
    	} else {
    		return false;
    	}
    }
}

3. Report

affterString를 String Class에서 StringBuffer Class로 수정하여 실행하니 실행 속도가 3배 빨랐다.