59. Scan Memory for Three Consecutive Increasing Values

#include <stdio.h>

int find_pattern(int *mem, int n) {
    if (n < 1) return -1;

    for (int i=1; i<n-1; i++) {
        if ((*(mem + i) - *(mem + i - 1) == 1) && (*(mem+i+1) - *(mem+i) == 1)) return i-1;
    }
    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;
}