Binary Search in Sorted Array

#include <stdio.h>
#include <stdint.h>

int binary_search(uint8_t *arr, uint8_t n, uint8_t key) {
    int l = 0, r = n - 1;
    while (l <= r) {
        int c = (r + l) / 2;
        if (arr[c] == key) { 
            return c;
        } else if (arr[c] < key) {
            l = c + 1;
        } else {
            r = c - 1;
        }
    }
    return -1;
}

int main() {
    uint8_t n, key;
    scanf("%hhu", &n);
    uint8_t arr[100];

    for (uint8_t i = 0; i < n; i++) {
        scanf("%hhu", &arr[i]);
    }
    scanf("%hhu", &key);

    int index = binary_search(arr, n, key);
    printf("%d", index);
    return 0;
}