Integer to English Words
Convert a non-negative integer to its english words representation. Given input is guaranteed to be less than 231 – 1. [Problem Link] Create a...
[Leetcode] Binary Tree Right Side View
[Problem Link] Given a binary tree, imagine yourself standing on the right side of it, return the values of the nodes you can see...
[Leetcode] One Edit Distance
[Problem Link] If you’ve solved the edit distance dynamic programming problem, this problem should be straightforward. Make sure to return false if both strings...
[Hackerrank] Pairs
You will be given an array of integers and a target value. Determine the number of pairs of array elements that have a difference...
[Leetcode] Unique Paths II
[Problem Link] Total paths ending at [i, j] are Total paths ending at [i+1, j] + Total paths ending at [i, j+1]Total paths ending...
[Leetcode] Course Schedule II
[Problem link] What is topological sort? You simply keep picking nodes with no incoming edges (or with in-order 0). No valid solution? You might...
[Leetcode] Container With Most Water
[Problem Link] Use a typical 2 pointer approach to solve this problem. At step 1 assume your max container spans two ends. What is...
[Leetcode] Random Pick Index
Given an array of integers with possible duplicates, randomly output the index of a given target number. You can assume that the given target...
[Leetcode] Moving Average from Data Stream
Given a stream of integers and a window size, calculate the moving average of all integers in the sliding window. Example: MovingAverage m =...
Chemistry 101
Basic Information Number of protons in the element define the element. Neutrons can change, electrons can change, but if protons change you have a...