#include <stdio.h> int find_pattern(int *mem, int n) { 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; }
Test Cases
Test Results
Input
8 2 4 5 6 9 11 12 14
Expected Output
1