#include <stdio.h>
#define SIZE 100

int linearSearch(const int array[], int key, size_t size);

int main(void) {
    int a[SIZE] = {0};

    for (size_t x = 0; x < SIZE; ++x) {
        a[x] = 2 * x;
    }

    int searchKey = 36;
    int subscript = linearSearch(a, searchKey, SIZE);

    if (subscript != -1) {
        printf("Found value at subscript %d\n", subscript);
    } else {
        printf("Value not found\n");
    }

    return 0;
}

int linearSearch(const int array[], int key, size_t size) {
    if (size == 0) {
        return -1;
    }
    if (array[size - 1] == key) {
        return size - 1;
    }
    return linearSearch(array, key, size - 1);
}