SWE Prep

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Question: Invert a binary tree. Input: 4 / \ 2 7 / \ / \ 1 3 6 9 Output: 4 / \ 7 2 / \ / \ 9 6 3 1 Solution Approach 1: Recursive The inverse of an emp…

Apr 14

Alice and Bob take turns playing a game, with Alice starting first. Initially, there is a number N on the chalkboard. On each player's turn, that playe…

Apr 7

Question: Given a non-empty array of integers nums, every element appears twice except for one. Find that single one. Solution Approach 1: Hash Table W…

Mar 31

Given an array A of integers, for each integer A[i] we may choose any x with -K <= x <= K, and add x to A[i]. After this process, we have some array B.…

Mar 24

Lessons Learned: TreeSet, Array Manipulation

Mar 7

Question: Implement an algorithm to print all valid (properly opened and closed) combinations of n pairs of parentheses.

Feb 28

Lessons Learned: Array parsing

Feb 21

The problem: Given two words (start and end), and a dictionary, find the length of shortest transformation sequence from start to end.

Feb 14

Lessons learned: DFS

Feb 4

Question: Given a string s and a dictionary of words dict, determine if s can be segmented into a space-separated sequence of one or more dictionary wo…

Jan 27

👋 Hello! I’m gathering feedback on SWE Prep. If you like to provide suggestions or feedback, let us know on this survey here! Question: Given a string…

Jan 22

Lesson: Array Manipulation

Jan 14

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