【LeetCode】9. Palindrome Number

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. Follow up:

Coud you solve it without converting the integer to a string?

来源：力扣（LeetCode） 链接：https://leetcode-cn.com/problems/palindrome-number 著作权归领扣网络所有。商业转载请联系官方授权，非商业转载请注明出处。

so easy~

class Solution {
public:
    bool isPalindrome(int x) {
        if(x<0)return false;
        string s;
        while(x>0){
            s+=(x%10+'0');
            x=x/10;
        }
        for(int i=0;i<s.size()/2;i++){
            if(s[i]!=s[s.size()-1-i]){
                return false;
            }
        }//cout<<s<<endl;
        return true;
    }
};

最快的老哥

class Solution {
public:
    bool isPalindrome(int x) {
        if(x<0) return 0;
        long xx=0,xxx=x;
        while(x>0){
            xx=xx*10+x%10;
            x/=10;
        }
        return xx==xxx?1:0;
    }
};