Finding the n-th prime number that is palindrome in base K - c

Question

I recently asked a question about finding whether a number is palindrome in base K or not and I get my answer.
My Recent Question
Now I have a more complicated question, We will get two numbers n and k, and we must find the n-th prime number that is palindrome in base K.
For example if we get 8 and 10, we have 2 3 5 7 11 101 131 151 which are palindrome and prime and so the answer is 151. Another example is 4 2 we have 3 5 7 17 respectively 11 101 111 10001 in base 2 which are prime and palindrome in base so the answer is 17.
n and k are given such that the answer is at most, 1E7.
I submit my program in a judge system and It gave wrong answer in some cases and also Time Limit error in one case. I don't know which part of my algorithm is wrong and what part of it is not optimised.
Note that I am not allowed to use array,vector and strings and also I cannot use libraries more than stdio.h and math.h. It is my program, Can anyone find any problems in it: (I defined intPow because the pow function in math, gives a float and sometime it causes problems)
#include <stdio.h>
#include <math.h>
int primeCheck ( int n);
int palindrome ( int n,int base);
int digitCountBase (int n , int base);
int intPow (int a , int b);
int main()
{
int n;
int base;
scanf("%d %d",&n,&base);
int counter = 0;
int i =2;
int firstRound =1;
while (counter!=n)
{
if (primeCheck(i))
{
if (palindrome (i,base))
{
counter++;
}
}
if (counter ==n)
{
break;
}
if (firstRound)
{
i++;
firstRound=0;
}
else{i+=2;}
}
printf("%d",i);
return 0;
}
int primeCheck ( int n)
{
if (n<2)
{
return 0;
}
if (n==4)
{
return 0;
}
else if (n<=5)
{
return 1;
}
if (n%2 ==0 || n%3 ==0 || n% 5 ==0)
{
return 0;
}
int i =5;
int limit = sqrt(n)+2;
for (int i =5;i<=limit;i+=6)
{
if (n%i==0||n%(i+2)==0)
{
return 0;
}
}
return 1;
}
int palindrome ( int n,int base)
{
int isTrue = 1;
int digitCount = digitCountBase(n,base);
int power = intPow(base,digitCount-1);
while (n>0&& digitCount >0)
{
if (n%base != (n/power)&&digitCount!=1)
{
isTrue =0;
return 0;
}
n = n- power;
n=n/base;
power = power /base;
power = power /base;
digitCount=digitCount-2;
}
return isTrue;
}
int digitCountBase (int n , int base)
{
int digits=0;
while (n)
{
digits++;
n = n / base;
}
return digits;
}
int intPow (int a , int b)
{
int result = 1;
for (int i=1;i<=b;i++)
{
result = result * a;
}
return result;
}

Answer 1

Solution: change palindrome to
int palindrome ( int n,int base)
{
int isTrue = 1;
int digitCount = digitCountBase(n,base);
int power = intPow(base,digitCount-1);
int original = n;
while (n>0&& digitCount >0)
{
if (n%base != (original/power) % base &&digitCount!=1)
{
isTrue =0;
return 0;
}
n=n/base;
power = power /base;
digitCount=digitCount-2;
}
return isTrue;
}
How did I find the error:
You are doing only 2 things, primality testing and palindrome testing, so makes sense to check if these are working fine.
Primality testing is easy, count primes from 1 to 10^7 and compare to known values on google. In this case, this works
To test palindrome, pick a working solution from the internet (even if you can´t submit their solution that uses arrays/strings, you can test with them!). Then iterate from 1 to 10^7 in a certain base and check that both functions return the same.
Testing with base 3, quickly saw that 56 was not giving same output. And the incorrect one was yours.
Then its a matter of fixing your function, which you now know which one is the problem and even have an example of where its not working