В чём собственно ошибка?

Question

#include <iostream>
#include <cmath>
using namespace std;

bool isPalindrome(int x) {
//завершите функцию
int a,b,c,n=0;
a=x;
do
{ c = a % 10;
b = (b * 10) + c;
n++;
a=a/10;
}
while (a != 0);
b=(b*10)+(x/pow(10,n));
if (x==b){
return true ;
}
else {
return false ;}
}

int main() {
int n;
cin >>n;

if(isPalindrome(n)) {
cout <<n<<" is a palindrome";
}
else {
cout << n<<" is NOT a palindrome";
}
return 0;
}

Answer 1

#include <iostream>
using namespace std;

bool isPalindrome(int x) {
int num, rem, rev=0;
num=x;
while(x != 0)
{
rem = x%10;
rev= rev*10 + rem;
x /= 10;
}
if (rev==num)
{
return true;
}
else
{
return false;
}
}
int main()
{
int n;
cin >>n;
if(isPalindrome(n)) {
cout <<n<<" is a palindrome";
}
else {
cout << n<<" is NOT a palindrome";
}
return 0;
}

Answer 2

Correct code)

#include <iostream>
#include <cmath>
using namespace std;

bool isPalindrome(int x) {
//завершите функцию
int a,b=0,c;
a=x;
do
{ c = a % 10;
b = (b * 10) + c;
a=a/10;
}
while (a != 0);
if (x==b){
return true ;
}
else {
return false ;}
}

int main() {
int n;
cin >>n;

if(isPalindrome(n)) {
cout <<n<<" is a palindrome";
}
else {
cout << n<<" is NOT a palindrome";
}
return 0;
}