Find the maximum of an array using recursion in C Solution, output & explanation

#include <stdio.h>

int max_of(const int *a, int n) {
    if (n == 1)
        return a[0];                        /* base case: one element */
    int rest = max_of(a + 1, n - 1);        /* max of the remaining elements */
    return a[0] > rest ? a[0] : rest;
}

int main(void) {
    int a[] = {17, 42, 8, 99, 23};
    printf("max = %d\n", max_of(a, 5));
    return 0;
}

max = 99