Ex2.Recursion

#include <iostream>
#include <bits/stdc++.h>

using namespace std;

const int SIZE = 100;
int digitSum(int number);
int arraySteps(int a[], int sp, int n);

int main()
{
    int n, spos;
    int a[SIZE];
    do
    {
        cout << "Enter n: ";
        cin >> n;
    }
    while (n < 0 || n >= SIZE);

    do
    {
        cout << "Enter start position: ";
        cin >> spos;
    }
    while (spos < 0 || spos >= n);

    cout << "Enter array: ";
    for (int i = 0; i < n; i++)
    {
        cin >> a[i];
    }
    cout << "Steps count: " << arraySteps(a, spos, n) << endl;

    return 0;
}

int digitSum(int number)
{
    if (number == 0)
    {
        return 0;
    }
    return (number % 10) + digitSum(number / 10);
}

int arraySteps(int a[], int sp, int n)
{
    if (sp < 0 || sp >= n || a[sp] == INT_MIN)
    {
        return 0;
    }
    else if (digitSum(a[sp]) % 2 == 0)
    {
        a[sp] = INT_MIN;
        return 1 + arraySteps(a, sp + 3, n);
    }
    a[sp] = INT_MIN;
    return 1 + arraySteps(a, sp - 2, n);
}