Recursive Function to find Max value between 2 integers - c++

Question

I'm trying to create a recursive function that finds the maximum number in an array between a low and a high integers.
I have tried this function that helps find the maximum element in array recursively. I'm just having trouble on how to add to the function that takes in a low and a high integers to find the max between those 2.
int findMaxRec(int A[], int n)
{
// if n = 0 means whole array has been traversed
if (n == 1)
return A[0];
return max(A[n-1], findMaxRec(A, n-1));
}
the goal is to have a function that looks something like this:
int findMaxBetwen(int A[], int low, int high){
//Here is where I need help integrating if lets say the array is A[] = 5,6,7,8
// Call findMaxBetwen(A[], 5, 8) and the output gives 7 because that is the max between the 3
//integers.
}

Answer 1

update: C++17 now defines a function std::size that can return the size of an array.
#include <iostream>
#include <iterator>
using namespace std;
int findMaxRec(const int[] A, const int &n)
{
if (n <= 0) throw "error: array is empty...";
if (n == 1) return A[0];
return std::max(A[n - 1], findMaxRec(A, (n - 1)));
}
int findMaxRec(const int[] A)
{
return findMaxRec(A, std::size(A));
}
const int& findMaxRec(const int &i)
{
return i;
}
If you dont have C++17, would you consider using a list?
#include <algorithm>
#include <list>
int findMaxRec(const std::list<int> &L)
{
if (L.size() == 0) throw "error: list is empty...";
return (*std::max_element(L.begin(), L.end()));
}
findMaxBetwen can be implemented as a function template:
template<typename T> int findMaxBetwen(const T &data, int low, int high)
{
int i = findMaxRec(data);
if (i <= low) return low;
if (i >= high) return high;
return i;
}
//....
int main(int argc, char** argv)
{
std::list<int> a = {5, 6, 7, 8, 10};
cout << findMaxBetween(a, 5, 8) << '\n'; // output is 8
int b[5] = {5, 6, 7, 8, 10};
cout << findMaxBetween(b, 5, 8) << '\n'; // output is 8
int c = 7;
cout << findMaxBetween(c, 5, 8) << '\n'; // output is 7
}
Learn more about function templates at cppreference