3 sequential numbers

Alright geniuses, if you think your programming ability is up to par, lets see you solve this:

Write an algorithm which in O(n) time finds 3 indices i, j, and k such that i < j < k and array[i] < array[j] < array[k].

>>43
The first and last steps definitely are. I'm not 100% sure about the second, but I think it's O(n). It looks at each element of the sublists at most one time.