In this article, we’ll explore why LeetCode Medium Problems is an excellent resource for experienced professionals and how to sharpen their skills.
Table of Contents
1. What Are Leetcode Medium Problems?
Leetcode medium problems are a step up from easy problems in terms of complexity and often require an intermediate understanding of algorithms and data structures. These problems commonly introduce dynamic programming, recursion, sorting, graph traversal, and combinatorics — essential concepts in technical interviews.
For beginners, these problems may appear overwhelming, but they lay the foundation for understanding harder challenges.
2. Why You Should Solve Medium Leetcode Questions
Medium Leetcode questions offer numerous benefits:
- Improves Problem-Solving: They teach you to break down complex scenarios.
- Prepares for Interviews: Most tech giants ask medium-level problems during coding interviews.
- Boosts Programming Confidence: Mastering them builds confidence for harder challenges.
3. Effective Tips for Solving Medium Leetcode Problems
- Master the Basics: Ensure you have a clear understanding of data structures like arrays, linked lists, trees, and hash maps.
- Focus on Patterns: Recognize problem-solving patterns (e.g., sliding window, divide and conquer).
- Practice Regularly: Consistency is key to mastering medium Leetcode questions.
- Analyze Solutions: Learn from the discussion section to understand diverse approaches.
- Leverage Tags: Use Leetcode tags like “dynamic programming” or “binary search” to group problems by concept.
4. Should You Prioritize Medium Leetcode Problems?
Yes! These problems are the sweet spot for learning. They cover core concepts without being overwhelmingly complex, making them perfect for improving technical interview readiness.
List of all Leetcode Problem
1. Easy Problems
2. Medium Problems
3. Hard Problems
Medium LeetCode Problems
| # | Problem | Level | Solution |
| 1 | Binary Tree Level Order Traversal | Medium | Link |
| 2 | Water And Jug Problem | Medium | Link |
| 3 | Beautiful Arrangement | Medium | Link |
| 4 | Longest Word in Dictionary through Deleting | Medium | Link |
| 5 | Longest Uncommon Subsequence II | Medium | Link |
| 6 | Predict the Winner | Medium | Link |
| 7 | Magical String | Medium | Link |
| 8 | Heaters | Medium | Link |
| 9 | Ones and Zeroes | Medium | Link |
| 10 | Number of Boomerangs | Medium | Link |
| 11 | Maximum XOR of Two Numbers in an Array | Medium | Link |
| 12 | Queue Reconstruction by Height | Medium | Link |
| 13 | Combination Sum IV | Medium | Link |
| 14 | Pacific Atlantic Water Flow | Medium | Link |
| 15 | Exclusive Time of Functions | Medium | Link |
| 16 | Continuous Subarray Sum | Medium | Link |
| 17 | Target Sum | Medium | Link |
| 18 | Total Hamming Distance | Medium | Link |
| 19 | Random Pick Index | Medium | Link |
| 20 | Flatten Nested List Iterator | Medium | Link |
| 21 | Increasing Triplet Subsequence | Medium | Link |
| 22 | H-Index II | Medium | Link |
| 23 | Design Add and Search Words Data Structure | Medium | Link |
| 24 | Course Schedule II | Medium | Link |
| 25 | Minimum Size Subarray Sum | Medium | Link |
| 26 | Binary Search Tree Iterator | Medium | Link |
| 27 | Clone Graph | Medium | Link |
| 28 | Longest Consecutive Sequence | Medium | Link |
| 29 | Partition Equal Subset Sum | Medium | Link |
| 30 | Game of Life | Medium | Link |
| 31 | Best Time to Buy and Sell Stock with Transaction Fee | Medium | Link |
| 32 | Trim a Binary Search Tree | Medium | Link |
| 33 | Next Greater Element III | Medium | Link |
| 34 | Number of Provinces | Medium | Link |
| 35 | Add Two Numbers II | Medium | Link |
| 36 | String Compression | Medium | Link |
| 37 | Lexicographical Numbers | Medium | Link |
| 38 | Find the Duplicate Number | Medium | Link |
| 39 | H-Index | Medium | Link |
| 40 | Kth Smallest Element in a BST | Medium | Link |
| 41 | Implement Trie Prefix Tree | Medium | Link |
| 42 | LRU Cache | Medium | Link |
| 43 | Factorial Trailing Zeroes | Medium | Link |
| 44 | Palindrome Partitioning | Medium | Link |
| 45 | Populating Next Right Pointers in Each Node II | Medium | Link |
| 46 | Path Sum II | Medium | Link |
| 47 | Construct Binary Tree from Preorder and Inorder Traversal | Medium | Link |
| 48 | Binary Tree Zigzag Level Order Traversal | Medium | Link |
| 49 | 3Sum Closest | Medium | Link |
| 50 | Container with Most Water | Medium | Link |
| 51 | Out of Boundary Paths | Medium | Link |
| 52 | Arithmetic Slices | Medium | Link |
| 53 | Integer Replacement | Medium | Link |
| 54 | Longest Substring with at least K Repeating Characters | Medium | Link |
| 55 | Peeking Iterator | Medium | Link |
| 56 | Course Schedule | Medium | Link |
| 57 | Compare Version Numbers | Medium | Link |
| 58 | Reverse Words in a String | Medium | Link |
| 59 | Reverse Integer | Medium | Link |
| 60 | Maximum Length of Pair Chain | Medium | Link |
| 61 | Convert BST to Greater Tree | Medium | Link |
| 62 | Solve the Equation | Medium | Link |
| 63 | Optimal Division | Medium | Link |
| 64 | Complex Number Multiplication | Medium | Link |
| 65 | Split Linked List in Parts | Medium | Link |
| 66 | Top K Frequent Words | Medium | Link |
| 67 | Maximum Width of Binary Tree | Medium | Link |
| 68 | Encode and Decode Tinyurl | Medium | Link |
| 69 | K Diff Pairs in an Array | Medium | Link |
| 70 | Minesweeper | Medium | Link |
| 71 | Longest Palindromic Subsequence | Medium | Link |
| 72 | Most Frequent Subtree Sum | Medium | Link |
| 73 | Sort Characters by Frequency | Medium | Link |
| 74 | Serialize and Deserialize BST | Medium | Link |
| 75 | Find All Anagrams in a String | Medium | Link |
| 76 | Rotate Function | Medium | Link |
| 77 | Insert Delete Getrandom O(1) | Medium | Link |
| 78 | Design Twitter | Medium | Link |
| 79 | Search a 2D Matrix II | Medium | Link |
| 80 | Product of Array Except Self | Medium | Link |
| 81 | Lowest Common Ancestor of a Binary Tree | Medium | Link |
| 82 | Lowest Common Ancestor of a Binary Search Tree | Medium | Link |
| 83 | Kth Largest Element in an Array | Medium | Link |
| 84 | Count Primes | Medium | Link |
| 85 | Number of Islands | Medium | Link |
| 86 | Binary Tree Right Side View | Medium | Link |
| 87 | Word Break | Medium | Link |
| 88 | Copy List with Random Pointer | Medium | Link |
| 89 | Letter Combinations of a Phone Number | Medium | Link |
| 90 | String to Integer | Medium | Link |
| 91 | Mini Parser | Medium | Link |
| 92 | Replace Words | Medium | Link |
| 93 | Minimum Height Trees | Medium | Link |
| 94 | Super Ugly Number | Medium | Link |
| 95 | Maximum Product of Word Lengths | Medium | Link |
| 96 | Wiggle Sort II | Medium | Link |
| 97 | Verify Preorder Serialization of a Binary Tree | Medium | Link |
| 98 | Count Numbers with Unique Digits | Medium | Link |
| 99 | Largest Divisible Subset | Medium | Link |
| 100 | Remove Duplicate Letters | Medium | Link |
| 101 | Find K Pairs with Smallest Sums | Medium | Link |
| 102 | Guess Number Higher or Lower II | Medium | Link |
| 103 | Kth Smallest Element in a Sorted Matrix | Medium | Link |
| 104 | Linked List Random Node | Medium | Link |
| 105 | Longest Absolute File Path | Medium | Link |
| 106 | UTF-8 Validation | Medium | Link |
| 107 | Decode String | Medium | Link |
| 108 | Evaluate Division | Medium | Link |
| 109 | Nth Digit | Medium | Link |
| 110 | Remove K Digits | Medium | Link |
| 111 | Diagonal Traverse | Medium | Link |
| 112 | Non Decreasing Array | Medium | Link |
| 113 | Split Array into Consecutive Subsequences | Medium | Link |
| 114 | Find K Closest Elements | Medium | Link |
| 115 | Find Duplicate Subtrees | Medium | Link |
| 116 | Delete Operation for Two Strings | Medium | Link |
| 117 | Shopping Offers | Medium | Link |
| 118 | Shortest Unsorted Continuous Subarray | Medium | Link |
| 119 | 01 Matrix | Medium | Link |
| 120 | Subarray Sum Equals K | Medium | Link |
| 121 | Construct Binary Tree from Inorder and Postorder Traversal | Medium | Link |
| 122 | Partition to K Equal Sum Subsets | Medium | Link |
| 123 | Sum of Square Numbers | Medium | Link |
| 124 | Find Largest Value in each Tree Row | Medium | Link |
| 125 | Can I Win | Medium | Link |
| 126 | Isomorphic Strings | Medium | Link |
| 127 | Friend Requests II Who has the Most Friends | Medium | Link |
| 128 | Beautiful Arrangement II | Medium | Link |
| 129 | Contiguous Array | Medium | Link |
| 130 | Brick Wall | Medium | Link |
| 131 | Task Scheduler | Medium | Link |
| 132 | Palindromic Substrings | Medium | Link |
| 133 | Maximum Swap | Medium | Link |
| 134 | Number of Longest Increasing Subsequence | Medium | Link |
| 135 | Accounts Merge | Medium | Link |
| 136 | Generate Parentheses | Medium | Link |
| 137 | Find Peak Element | Medium | Link |
| 138 | Fraction to Recurring Decimal | Medium | Link |
| 139 | Perfect Squares | Medium | Link |
| 140 | Best Time to Buy and Sell Stock with Cooldown | Medium | Link |
| 141 | Investments in 2016 | Medium | Link |
| 142 | Majority Element II | Medium | Link |
| 143 | Non Decreasing Subsequences | Medium | Link |
| 144 | Employee Importance | Medium | Link |
| 145 | Delete Node in a BST | Medium | Link |
| 146 | House Robber III | Medium | Link |
| 147 | Top K Frequent Elements | Medium | Link |
| 148 | Validate IP Address | Medium | Link |
| 149 | Minimum Genetic Mutation | Medium | Link |
| 150 | Integer to Roman | Medium | Link |
| 151 | Find All Duplicates in an Array | Medium | Link |
| 152 | Longest Repeating Character Replacement | Medium | Link |
| 153 | Remove Comments | Medium | Link |
| 154 | Bulb Switcher II | Medium | Link |
| 155 | Maximum Binary Tree | Medium | Link |
| 156 | 2 Keys Keyboard | Medium | Link |
| 157 | Permutation in String | Medium | Link |
| 158 | Find Bottom Left Tree Value | Medium | Link |
| 159 | Minimum Number of Arrows to Burst Balloons | Medium | Link |
| 160 | Battleships in a Board | Medium | Link |
| 161 | Longest Increasing Subsequence | Medium | Link |
| 162 | House Robber II | Medium | Link |
| 163 | Find Minimum in Rotated Sorted Array | Medium | Link |
| 164 | Populating Next Right Pointers in Each Node II | Medium | Link |
| 165 | Repeated DNA Sequences | Medium | Link |
| 166 | Maximum Product Subarray | Medium | Link |
| 167 | Evaluate Reverse Polish Notation | Medium | Link |
| 168 | 4Sum | Medium | Link |
| 169 | Minimum Moves to Equal Array Elements | Medium | Link |
| 170 | My Calendar II | Medium | Link |
| 171 | My Calendar I | Medium | Link |
| 172 | Longest Univalue Path | Medium | Link |
| 173 | Repeated String Match | Medium | Link |
| 174 | Redundant Connection | Medium | Link |
| 175 | Implement Magic Dictionary | Medium | Link |
| 176 | Populating Next Right Pointers in Each Node | Medium | Link |
| 177 | Flatten Binary Tree to Linked List | Medium | Link |
| 178 | Decode Ways | Medium | Link |
| 179 | Merge Intervals | Medium | Link |
| 180 | Running Total for Different Genders | Medium | Link |
| 181 | Team Scores in Football Tournament | Medium | Link |
| 182 | Highest Grade for each Student | Medium | Link |
| 183 | Restaurant Growth | Medium | Link |
| 184 | Find the Start and End Number of Continuous Ranges | Medium | Link |
| 185 | All People Report to the Given Manager | Medium | Link |
| 186 | Page Recommendations | Medium | Link |
| 187 | Last Person to Fit in the Bus | Medium | Link |
| 188 | Monthly Transactions I | Medium | Link |
| 189 | Product Price at a Given Date | Medium | Link |
| 190 | Immediate Food Delivery II | Medium | Link |
| 191 | Active Businesses | Medium | Link |
| 192 | Minimum Path Sum | Medium | Link |
| 193 | Unique Paths II | Medium | Link |
| 194 | Unique Paths | Medium | Link |
| 195 | Rotate List | Medium | Link |
| 196 | Project Employees III | Medium | Link |
| 197 | Spiral Matrix II | Medium | Link |
| 198 | Edit Distance | Medium | Link |
| 199 | Insert Interval | Medium | Link |
| 200 | Count And Say | Medium | Link |
| 201 | Product Sales Analysis III | Medium | Link |
| 202 | Two Sum II Input Array is Sorted | Medium | Link |
| 203 | Combinations | Medium | Link |
| 204 | Search a 2D Matrix | Medium | Link |
| 205 | Customers Who Bought All Products | Medium | Link |
| 206 | Set Matrix Zeroes | Medium | Link |
| 207 | Exchange Seats | Medium | Link |
| 208 | Shortest Distance in a Line | Medium | Link |
| 209 | Shortest Distance in a Plane | Medium | Link |
| 210 | Tree Node | Medium | Link |
| 211 | Managers with at Least 5 Direct Reports | Medium | Link |
| 212 | Game Play Analysis III | Medium | Link |
| 213 | Nth Highest Salary | Medium | Link |
| 214 | Rank Scores | Medium | Link |
| 215 | Consecutive Numbers | Medium | Link |
| 216 | Second Highest Salary | Medium | Link |
| 217 | Maximum Subarray | Medium | Link |
| 218 | Spiral Matrix | Medium | Link |
| 219 | Jump Game | Medium | Link |
| 220 | Validate Binary Search Tree | Medium | Link |
| 221 | Gray Code | Medium | Link |
| 222 | Subsets II | Medium | Link |
| 223 | Unique Binary Search Trees II | Medium | Link |
| 224 | Unique Binary Search Trees | Medium | Link |
| 225 | Sort Colors | Medium | Link |
| 226 | Subsets | Medium | Link |
| 227 | Remove Duplicates from Sorted List II | Medium | Link |
| 228 | Partition List | Medium | Link |
| 229 | Simplify Path | Medium | Link |
| 230 | Search in Rotated Sorted Array II | Medium | Link |
| 231 | Remove Duplicates from Sorted Array II | Medium | Link |
| 232 | Valid Sudoku | Medium | Link |
| 233 | Recover Binary Search Tree | Medium | Link |
| 234 | Word Search | Medium | Link |
| 235 | Reverse Linked List II | Medium | Link |
| 236 | Interleaving String | Medium | Link |
| 237 | Find First and Last Position Of Element in Sorted Array | Medium | Link |
| 238 | Min Stack | Medium | Link |
| 239 | Pow(x,n) | Medium | Link |
| 240 | Group Anagrams | Medium | Link |
| 241 | Rotate Image | Medium | Link |
| 242 | Permutations II | Medium | Link |
| 243 | Jump Game II | Medium | Link |
| 244 | Combination Sum II | Medium | Link |
| 245 | Multiply Strings | Medium | Link |
| 246 | Combination Sum | Medium | Link |
| 247 | Swap Nodes in Pairs | Medium | Link |
| 248 | Permutations | Medium | Link |
| 249 | Search in Rotated Sorted Array | Medium | Link |
| 250 | Next Permutation | Medium | Link |
| 251 | Divide Two Integers | Medium | Link |
| 252 | Find the Index of the First Occurrence in a String | Medium | Link |
| 253 | Delete Node in a Linked List | Medium | Link |
| 254 | Convert Sorted List to Binary Search Tree | Medium | Link |
| 255 | House Robber | Medium | Link |
| 256 | Maximal Square | Medium | Link |
| 257 | Basic Calculator II | Medium | Link |
| 258 | Longest Palindromic Substring | Medium | Link |
| 259 | Zigzag Conversion | Medium | Link |
| 260 | 3Sum | Medium | Link |
| 261 | Longest Substring without Repeating Characters | Medium | Link |
| 262 | Add Two Numbers | Medium | Link |
| 263 | Best Time to Buy and Sell Stock II | Medium | Link |
FAQs
1. How Many Medium Problems Are on Leetcode?
Leetcode offers over 1,200 medium-level problems across different domains. They update their database regularly for better coverage of industry-relevant problems.
2. Which Are the Best Leetcode Medium Questions for Beginners?
Easy-to-tackle medium problems for starters include:
– Two Sum II – Input Array Is Sorted
– Letter Combinations of a Phone Number
– Word Search
How Long Does It Take to Solve Medium Leetcode Questions?
Medium Leetcode Questions depend on the individual’s experience. Beginners may take 30-60 minutes per problem, while experienced programmers might solve them in 15-30 minutes.
Conclusion
Whether you’re preparing for a job interview or honing your coding skills, medium Leetcode problems are essential. With regular practice and a problem-solving mindset, you’ll build a strong foundation to tackle harder problems. Start today, and you’ll see yourself improve in no time!
Is there a specific problem you’re facing while solving Leetcode medium questions? Let us know in the comments below!
Happy Reading…