#include <iostream>
#include <cstddef>
 
int* find(int target, int* start, int* stop)
{    
    while (start < stop)
    {
        if (*start == target)
        {
            return start;
        }    
        ++start;
    }
 
    return nullptr;
}
 
int main()
{
    int someArray[] = {3,10,19,7,3,45,123,4,9,89};
 
    int *start = &someArray[0];
    int *stop = &someArray[10];
 
    std::cout << "Enter a number to find: ";
 
    int num;
    std::cin >> num;
 
    int *found = find(num, start, stop);
    if (found)
        std::cout << "Found at index " << static_cast<ptrdiff_t>(found - start);
    else
        std::cout << "Not found";
 
    return 0;
}

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ODk=

89