Leetcode 题目解析之 Palindrome Number

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

Some hints:

1. Could negative integers be palindromes? (ie, -1)
2. If you are thinking of converting the integer to string, note the restriction of using extra space.
3. 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?
4. There is a more generic way of solving this problem.

代码语言：javascript复制

    public boolean isPalindrome(int x) {
        if (x < 0) {
            return false;
        }
        if (x >= 0 && x < 10) {
            return true;
        }
        int d = 1;
        while (x / d >= 10) {
            d *= 10;
        }
        while (x != 0) {
            if (x % 10 != x / d) {
                return false;
            }
            x = x % d / 10;
            d /= 100;
        }
        return true;
    }

case integer overflow palindrome space

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