Scan Memory for Three Consecutive Increasing Values

#include <stdio.h>

int find_pattern(int *mem, int n) {
    // Write your pointer-based logic here
    int *a= mem;
    int i=0;
    int dem=0;
    while (i<n)
    {
        if((*a==*(a+1) -1 )&& (*a=*(a+2)-2)) 
        {
            return i;
            dem++;
        }
        i++;
        a++;
    }
    if(dem==0) return -1;
}

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

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

    int res = find_pattern(arr, n);
    printf("%d", res);

    return 0;
}