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// Author : yqtao// Date   : 2016-7-3// Email  : yqtao@whu.edu.cn/************************************************************************************ Determine whether an integer is a palindrome.Do this without extra space.*** Some hints :** 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.**********************************************************************************/#include
   
    using namespace std;//Solutin 1bool isPalindrome(int x) {    if (x < 0 || (x != 0 && x % 10 == 0)) {
           return false;    }    long long result = 0;   //using long long it can not be overflow    int temp = x;    while (temp)      //revere the num;    {
           result = result * 10 + temp % 10;        temp /= 10;        if (result>INT_MAX)    //if overflow ,it must be return false            return false;    }    return x ==result;}//Solutin 2 bool isPalindrome1(int x) {    if (x < 0 || (x != 0 && x % 10 == 0)) {
           return false;    }    int half = 0;        while (x > half) {                half = half * 10 + x % 10;        x /= 10;    }    if (half == x || half / 10 == x) {
           return true;    }    return false;}int main(){    cout << boolalpha << isPalindrome(121) << endl;}
   

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