LeetCode Palindrome Number

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

click to show spoilers.

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.

思路：復習了sprintf(): 把格式化的數據寫入某個字符串緩沖區。

class Solution {
public:
    bool isPalindrome(int x) {
        if (x < 0) return false;
        
        char buf[100];
        sprintf(buf, "%d", x);
        string b = buf;
        int len = b.length();
        for (int i = 0; i < len/2; i++) {
            if (b[i] != b[len-1-i])
                return false;
        }
        
        return true;
    }
};