Leetcode 9. Palindrome Number（水）

9. Palindrome Number

Easy

Determine whether an integer is a palindrome. An integer is a palindrome when it reads the same backward as forward.

Example 1:

Input: 121
Output: true

Example 2:

Input: -121
Output: false
Explanation: From left to right, it reads -121. From right to left, it becomes 121-. Therefore it is not a palindrome.

Example 3:

Input: 10
Output: false
Explanation: Reads 01 from right to left. Therefore it is not a palindrome.


题解：计算倒过来的数是多少，判断两个数是否相等就行

class Solution {
public:
    bool isPalindrome(int x) {
        if(x < 0 ) return false;
        long long lx = 0,rx = x;
        while(rx > 0){
            lx = lx*10+rx%10;
            rx /= 10;
        }
        if(lx==x) return true;
        else return false;
    }
};

Runtime: 8 ms, faster than 90.24% of C++ online submissions for Palindrome Number.

Memory Usage: 8.2 MB, less than 74.55% of C++ online submissions for Palindrome Number.