9. Palindrome Number

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

Some hints:

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

public class Solution {
    public boolean isPalindrome(int x) {
        if(x < 0) return false;
        
        int ret = reverse(x);
         if(ret == x) return true;
         else return false;
    }
    
    public int reverse(int x) {
        long ret = 0; //long in order to avoid overflow
        
        if(x == java.lang.Integer.MIN_VALUE) return 0; //Avoid overflow
        x = Math.abs(x);
        while(x != 0){
            ret = ret *10 + x%10;
            x /= 10;
        }

        if(ret > java.lang.Integer.MAX_VALUE || ret < java.lang.Integer.MIN_VALUE) return 0;
        return (int) ret;
    }
}

 

posted on 2016-05-30 09:28  joannae  阅读(141)  评论(0编辑  收藏  举报

导航