Zadachi

#include <stdio.h>
#include <stdlib.h>

int factorial(int n)
{
    if (n == 0)
    {
        return 1;
    }
    return factorial(n - 1) * n;
}

void countDown(int n)
{
    if (n == 0)
    {
        return;
    }
    for (int i = 0; i < n; i++)
    {
        printf("*");
    }
    printf("\n");

    countDown(n - 1);

    for (int i = 0; i < n; i++)
    {
        printf("*");
    }
    printf("\n");
}

int sum(int n)
{
    if (n == 0)
    {
        return 0;
    }
    return sum(n - 1) + n;
}

int sumArr(int* arr, int size, int start)
{
    if (start == size)
    {
        return 0;
    }
    return arr[start] + sumArr(arr, size, start + 1);
}

int main()
{
    int arr[] = {2, 1, 8, 7, 9};
    printf("%d\n", sumArr(arr, 5, 0));
    return 0;
}