Detect Alternating Pattern

Code

#include <stdio.h>

int is_alternating_pattern(int *mem, int k) {
    /* validate input */
    if (!mem) return -1; 

    int *curr = mem; 
    int expected = *curr; 

    for (int i = 0; i < k; i++)
    {
        if (*curr != expected) return 0; 
        expected ^= 1; 
        curr++; 
    }
    
    return 1;
}

int main() {
    int n, k, arr[100];
    scanf("%d %d", &n, &k);

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

    int res = is_alternating_pattern(arr, k);
    printf("%d", res);

    return 0;
}

Solving Approach