DSA Solutions - Page 6

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

2096.Step-By-Step Directions From a Binary Tree Node to Another

2109.Adding Spaces to a String

2115.Find All Possible Recipes from Given Supplies

2116.Check if a Parentheses String Can Be Valid

2120.Execution of All Suffix Instructions Staying in a Grid

2125.Number of Laser Beams in a Bank

2131.Longest Palindrome by Concatenating Two Letter Words

2135.Count Words Obtained After Adding a Letter

2166.Design Bitset

2168.Unique Substrings With Equal Digit Frequency

2182.Construct String With Repeat Limit

2186.Minimum Number of Steps to Make Two Strings Anagram II

2207.Maximize Number of Subsequences in a String

2211.Count Collisions on a Road

2222.Number of Ways to Select Buildings

2232.Minimize Result by Adding Parentheses to Expression

2266.Count Number of Texts

2268.Minimum Number of Keypresses

2284.Sender With Largest Word Count

2288.Apply Discount to Prices

2311.Longest Binary Subsequence Less Than or Equal to K

2330.Valid Palindrome IV

2337.Move Pieces to Obtain a String

2343.Query Kth Smallest Trimmed Number

2370.Longest Ideal Subsequence

2375.Construct Smallest Number From DI String

2380.Time Needed to Rearrange a Binary String

2381.Shifting Letters II

2384.Largest Palindromic Number

2390.Removing Stars From a String

2391.Minimum Amount of Time to Collect Garbage

2405.Optimal Partition of String

2408.Design SQL

2414.Length of the Longest Alphabetical Continuous Substring

2434.Using a Robot to Print the Lexicographically Smallest String

2450.Number of Distinct Binary Strings After Applying Operations

2452.Words Within Two Edits of Dictionary

2456.Most Popular Video Creator

2483.Minimum Penalty for a Shop

2486.Append Characters to String to Make Subsequence

2489.Number of Substrings With Fixed Ratio

2512.Reward Top K Students

2516.Take K of Each Character From Left and Right

2522.Partition String Into Substrings With Values at Most K

2531.Make Number of Distinct Characters Equal

2539.Count the Number of Good Subsequences

2546.Apply Bitwise Operations to Make Strings Equal

2559.Count Vowel Strings in Ranges

2564.Substring XOR Queries

2575.Find the Divisibility Array of a String

How to use these solutions