0009 Palindrome Number

• Simple
• C++

问题概述

解题思路

class Solution
{
public:
    bool isPalindrome(int x)
    {

        std::string x_string1 = std::to_string(x);
        std::string x_string2 = x_string1;

        std::reverse(x_string1.begin(), x_string1.end());

        bool flag = x_string1 == x_string2;
        return flag;
    }
};

class Solution
{
public:
    bool isPalindrome(int x)
    {
        bool flag = false;
        int x_t = x;
        if (x < 0)
        {
            flag = false;
        }
        else
        {
            long long int x_reverse = 0;
            while (x > 0)
            {
                x_reverse = x_reverse * 10 + x % 10;
                x /= 10;
            }

            //std::cout << "x = " << x << std::endl;
            //std::cout << "x_reverse = " << x_reverse << std::endl;

            if (x_reverse == x_t)
            {
                flag = true;
            }
        }
        return flag;
    }
};

class Solution
{
public:
    bool isPalindrome(int x)
    {
        bool flag = true;
        std::string x_string = std::to_string(x);
        std::stack<char> stk;
        int mid = x_string.length() / 2;
        for (int i = 0; i < mid; i++)
        {
            stk.push(x_string[i]);
        }

        for (int i = (x_string.length() % 2 == 0 ? mid : mid + 1); i < x_string.length(); i++)
        {
            if (x_string[i] != stk.top())
            {
                flag = false;
                return flag;
            }
            stk.pop();
        }
        return flag;
    }
};