Trees and Recursion

Trees and recursion account for a good share of the coding problems Chewy candidates name. Intern and new-grad loops keep asking for plain binary search tree work, and phone screens and code tests add a twist or two.

Senior screens lean on backtracking, with follow-ups on what a null input does. Both backtracking problems here use the same recursion, where each call picks an item and hands the rest down. They differ in when a branch gets skipped.

On the tree problems, give each cost in terms of tree height and say what happens when sorted inserts turn the tree into a chain. On all of them, write the base case for an empty tree or a null string before the recursive case.

ChewyPremium lesson · Coding round

The 5 Chewy problems are below.

1. 1A Premium questionCoding · Easy
2. 2A Premium questionCoding · Easy
3. 3A Premium questionCoding · Medium

+ 2 more in this lesson

Each with hints, the follow-up and a tested solution.

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