LeetCode解题报告--Palindrome Number

题目：回文数字的判断

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

Some hints:

Could negative integers be palindromes? (ie, -1)

If you are thinking of converting the integer to string, note the restriction of using extra space.

You could also try reversing an integer. However, if you have solved the problem “Reverse Integer”, you know that the reversed integer might overflow. How would you handle such case?

There is a more generic way of solving this problem.

原题链接地址：https://leetcode.com/problems/palindrome-number/

分析：该题难度不大，题意是给定一个int型数字num，判断其是否为回文数字。主要有两种情况：

1. num >= 0, 当num = 00000, 含多个零时，要单独讨论；

2. num < 0, 先转为正数， 再进行判断。

Java 代码：（accepted）

public class PalindromeNuber {
    public static boolean isPlindrome(int x){
        if(x == 0) {
            x = 0;
        }
        String x1 = "" + x;
        StringBuffer x2 = new StringBuffer(x1); //Save reversed x1;

        if(x1.equals(x2.reverse().toString()))
            return true;
        else {
            return false;
        }
    }

    public static void main(String[] args) {
        int x = -2147447412;
        System.out.println(isPlindrome(x));
        int x1 = -0000000;
        System.out.println(isPlindrome(x1));
        int x2 = 103423;
        System.out.println(isPlindrome(x2));
        int x3 = -2192;
        System.out.println(isPlindrome(x3));
        int x4 = 00000;
        System.out.println(isPlindrome(x4));
    }
}

测试结果：

false
true
false
false
true

相关代码放在个人github:https://github.com/gannyee/LeetCode/tree/master/src

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