c_cpp 9.回文数

Posted 2021-05-14

//利用数字逆序进行对比
class Solution {
public:
    bool isPalindrome(int x) {
        if(x < 0) return false;
        if(x == 0) return true;
        int rst = 0,num = x;
        
        while(num != 0){
            rst = rst * 10 + num % 10;
            num /= 10;
        }
        return (rst == x) ? true:false;
    }
};

//将数字转换为字符串，然后头尾进行比较
//124ms
class Solution {
public:
    bool isPalindrome(int x) {
        if(x < 0)
            return false;
        string str = to_string(x);
        int start = 0;
        int end = str.length() - 1;
        if(str.length() <= 1)
            return true;
        for(;start <= end;start++,end--)
            if(str[start] != str[end])
                return false;
        return true;
    }
};