#include <stdio.h> int find_pattern(int *mem, int n) { // Write your pointer-based logic here if(!mem || n <= 0) return -1; int* p1 = mem; int* p2 = mem + 2; for(int i = 0; i < n - 2; i++) { if((*p1 == *(p1 + 1) - 1) && (*(p1 + 1) == *(p1 + 2) - 1)) return i; p1++; p2++; } 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; }
Test Cases
Test Results
Input
8 2 4 5 6 9 11 12 14
Expected Output
1