DSA Solutions - Page 5

Each solution breaks the problem into approaches, usually from brute force to the best one, and explains why each works. Code comes in Python, Java, C++ and other languages. Knowing why an approach works matters more in an interview than remembering the code.

Try the problem first. Give it at least 20 minutes before you open the solution.
Read every approach. The brute force shows you the problem; the faster ones show the pattern.
Check the complexity. Note the time and space of each approach and what makes the difference.
Write it yourself. Close the solution and code it from memory in the editor.
Come back in a week. Solving it again later is what makes the pattern stick.

All problems Topics Company questions Sheets

Solutions, explained

2477.Minimum Fuel Cost to Report to the Capital

2479.Maximum XOR of Two Non-Overlapping Subtrees

2509.Cycle Length Queries in a Tree

2538.Difference Between Maximum and Minimum Price Sum

2581.Count Number of Possible Root Nodes

2583.Kth Largest Sum in a Binary Tree

2603.Collect Coins in a Tree

2641.Cousins in Binary Tree II

2646.Minimize the Total Price of the Trips

2673.Make Costs of Paths Equal in a Binary Tree

2689.Extract Kth Character From The Rope Tree

2764.Is Array a Preorder of Some ‌Binary Tree

2773.Height of Special Binary Tree

2791.Count Paths That Can Form a Palindrome in a Tree

2792.Count Nodes That Are Great Enough

2846.Minimum Edge Weight Equilibrium Queries in a Tree

2867.Count Valid Paths in a Tree

2872.Maximum Number of K-Divisible Components

2920.Maximum Points After Collecting Coins From All Nodes

2925.Maximum Score After Applying Operations on a Tree

2973.Find Number of Coins to Place in Tree Nodes

3004.Maximum Subtree of the Same Color

3067.Count Pairs of Connectable Servers in a Weighted Tree Network

3068.Find the Maximum Sum of Node Values

3157.Find the Level of Tree with Minimum Sum

3203.Find Minimum Diameter After Merging Two Trees

3241.Time Taken to Mark All Nodes

3249.Count the Number of Good Nodes

3313.Find the Last Marked Nodes in Tree

3319.K-th Largest Perfect Subtree Size in Binary Tree

3327.Check if DFS Strings Are Palindromes

3331.Find Subtree Sizes After Changes

3367.Maximize Sum of Weights after Edge Removals

3372.Maximize the Number of Target Nodes After Connecting Trees I

3373.Maximize the Number of Target Nodes After Connecting Trees II

3558.Number of Ways to Assign Edge Weights I

3559.Number of Ways to Assign Edge Weights II

3562.Maximum Profit from Trading Stocks with Discounts

3585.Find Weighted Median Node in Tree

3590.Kth Smallest Path XOR Sum

3787.Find Diameter Endpoints of a Tree

3812.Minimum Edge Toggles on a Tree

3820.Pythagorean Distance Nodes in a Tree

3831.Median of a Binary Search Tree Level

3841.Palindromic Path Queries in a Tree

3965.Finish Time of Tasks I

3997.Count Dominant Nodes in a Binary Tree

4015.Weighted Sum of a Tree

How to use these solutions