Palindrome Number

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

判断一个integer是否为回文。注意不要用额外的空间。

另外，注意考虑负数。

 

public class Solution {
     public boolean isPalindrome(int x) {
        if(x<0){
            return false;
        }
        
        int count=0;
        int xx = x;
         while(x!=0) {  
                x=x / 10;  
                count++;
            }  
    //     System.out.println(count);
         
         int[] arr = new int[count];
         
         for(int i=0;i<count;i++) {  
             arr[i]=xx % 10;  
              
              xx /= 10;
            //  System.out.println(arr[i]); 
            }  
         
             int low = 0;
            int high = count - 1;
            while (low < high) {
              if (arr[low] != arr[high]){
                return false; // Not a palindrome
              }
              low++;
              high--;
            }

            return true; //is a palindrome
        }
}

 532 ms.