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