Updated at: 11 May 2019 15:45:33

Problems with array can be very difficult.

Exhaustive Search

!! Learn how to handle duplicates

Two Sum - Find two vals in the array that will sum to a specific value. O(n) 3Sum - Iterate through all starting value, then use Two Sum. O(n^2)

Binary Search

First and Last position of element in sorted array

Be very clear about the bounds