<div class="leaf flex"><div class="inner justify"><h4>Optional</h4><ul><li>Maximum Depth of Binary Tree</li><li>Same Tree</li><li>Binary Tree Level Order Traversal</li><li>Encode and Decode Strings (Leetcode Premium)</li></ul><h5>Week 4 - More Data Structures</h5><p>Week 4 builds up on knowledge from previous weeks but questions are of increased difficulty. Expect to see such level of questions during interviews. You get more practice on more advanced data structures such as (but not exclusively limited to 