https://www.rik-kisnah.ai/tags/hash-map/Recent content in Hash Map on Rik Kisnah - BlogHugoenTue, 13 Oct 2020 09:00:00 -0700https://www.rik-kisnah.ai/teach/coding/clone-graph/Tue, 13 Oct 2020 09:00:00 -0700https://www.rik-kisnah.ai/teach/coding/clone-graph/Make an exact copy of a graph where nodes point at each other, possibly in loops. The only new idea over a tree is a map from old node to new node, so you never copy anyone twice and never get stuck going round in circles.https://www.rik-kisnah.ai/teach/coding/two-sum/Tue, 14 Jun 2016 09:00:00 -0700https://www.rik-kisnah.ai/teach/coding/two-sum/Find two numbers in a list that add up to a target. Unsorted list: remember what you have seen in a hash map. Sorted list: one finger at each end, walk them towards each other. Two tricks, one problem, and half of the array questions you will ever be asked.