LeetCode之Palindrome Number（回文数）

1、题目

Determine whether an integer is a palindrome. Do this without extra space.

2、代码实现

代码实现1

public static boolean isPalindrome(int x) {if (x < 0) {return false;}String s = String.valueOf(x);char[] chars = s.toCharArray();int length = chars.length;for (int i = 0 ; i < length / 2; ++i) {if (chars[i] != chars[length - i -1]) {return false;}}return  true;}

代码实现2

public static boolean isPalindrome1(int x) {if (x < 0) {return false;}String s = String.valueOf(x);char[] chars = s.toCharArray();int start = 0;int end = chars.length - 1;while (start < end) {if (chars[start++] != chars[end--]) {return false;}}return true;}

注意这里是start < end,不是 start != end;比如 2 != 3 , 下一步 3 != 2,这样会下表越界，注意

 

切记不要搞错了，