#include <iostream>

using namespace std;

int count_x(char* p, char x)
{
    if (p == nullptr)
        return 0;

    int count = 0;

    for (; p != nullptr; ++p)
    {
        if (*p == x)
            ++count;
    }

    return count;
}

int main()
{
    char str[] = "foobar";
    cout << "Count: " << count_x(str, 'o') << "\n";

    return 0;
}