Detect Alternating Pattern

#include <stdio.h>

int is_alternating_pattern(int *mem, int k) {
    // Write your pointer logic here

    if (mem == NULL) return 0;
    if (k < 2) return 1;

    int first = *mem;
    int second = *(mem+1);

    bool even = true;

    for (size_t i = 2; i < k; i++) {
        if (even) {
            if (*(mem+i) != first) return 0;
        }
        else {
            if (*(mem+i) != second) return 0;
        }
        even = !even;
    }
    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;
}