#include <stdio.h> int find_pattern(int *mem, int n) { int i; for (i = 0; i < (n - 2); i++, mem++) { if ( (*(mem + 1) - *(mem + 0) == 1) && (*(mem + 2) - *(mem + 1) == 1) ) return i; } 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