#include <stdio.h> int find_pattern(int *mem, int n) { int count = 1; int curr, prev = *mem++; for (int i = 1; i < n; i++) { if (count == 3) return i-3; curr = *mem++; if (curr == prev+1) { count++; } else { count = 1; } prev = curr; } 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