leetcode-9-回文数

问题：

package com.nxz.blog.otherTest;

public class Test9PalindromeNumber {

/**
* 判断数字是否是回文
* 方法一：将数字转为字符串，在判断字符串是否是回文数字
* 方法二：之间判断数字，将number % 10 的余数链接后判断是否和源数字相等
*/
public boolean isPalindrome(int x) {
boolean isPalindrome = true;

String s = x + "";
int left = 0, right = s.length() - 1;
while (left <= right) {
if (s.charAt(left) != s.charAt(right)) {
isPalindrome = false;
break;
}
left++;
right--;
}

return isPalindrome;
}

public boolean isPalindrome2(int x) {
if (x < 0 || (x % 10 == 0 && x != 0)) {
return false;
}
int pre = 0;
while (x > pre) {
pre = pre * 10 + x % 10;
x /= 10;
}

return x == pre || x == pre / 10;
}

public static void main(String[] args) {
Test9PalindromeNumber t = new Test9PalindromeNumber();
boolean palindrome = t.isPalindrome2(12344321);
System.out.println(palindrome);
}
}