The Grind 75 LeetCode List
The Grind 75: the Blind 75 reworked into a week-by-week schedule that starts with the easiest high-yield problems and ends on the hard ones. Ordered for study, not by topic.
- 75 problems
- 23 Easy
- 43 Medium
- 9 Hard
- 21 patterns
Where this list comes from
The Grind 75 is not ours. It is a published selection that people work through by name, and we reproduce it here by problem number, in the order the list itself uses. What we add is the solution: of the 75 entries below, 75 carry a complete Python solution with a worked example and its time and space complexity.
The published list names 75 entries. All 75 resolve to a problem in this library and are listed below.
Every count on this page is computed from what the page renders, so the number in a heading is the number of rows under it. Nothing is padded to make a title's number come out right — that would be wrong in a way anyone who knows the list would spot in seconds.
All 75 problems, grouped by pattern
Each group is the pattern that most specifically solves those problems, so the list can be worked through a technique at a time instead of a problem at a time. Groups appear in the order the list itself introduces them.
Hash Map (3)
| # | Problem | Difficulty | Topics |
|---|---|---|---|
| 1 | Two Sum | Easy | Array, Hash Table |
| 383 | Ransom Note | Easy | Hash Table, String, Counting |
| 8 | String to Integer (atoi) | Medium | String |
Stack (7)
| # | Problem | Difficulty | Topics |
|---|---|---|---|
| 20 | Valid Parentheses | Easy | Stack, String |
| 232 | Implement Queue using Stacks | Easy | Stack, Design, Queue |
| 150 | Evaluate Reverse Polish Notation | Medium | Stack, Array, Math |
| 155 | Min Stack | Medium | Stack, Design |
| 42 | Trapping Rain Water | Hard | Stack, Array, Two Pointers +2 |
| 224 | Basic Calculator | Hard | Stack, Recursion, Math +1 |
| 84 | Largest Rectangle in Histogram | Hard | Stack, Array, Monotonic Stack |
Linked List (6)
| # | Problem | Difficulty | Topics |
|---|---|---|---|
| 21 | Merge Two Sorted Lists | Easy | Recursion, Linked List |
| 141 | Linked List Cycle | Easy | Hash Table, Linked List, Two Pointers |
| 206 | Reverse Linked List | Easy | Recursion, Linked List |
| 876 | Middle of the Linked List | Easy | Linked List, Two Pointers |
| 23 | Merge k Sorted Lists | Hard | Linked List, Divide and Conquer, Heap (Priority Queue) +1 |
| 146 | LRU Cache | Medium | Design, Hash Table, Linked List +1 |
Dynamic Programming (5)
| # | Problem | Difficulty | Topics |
|---|---|---|---|
| 121 | Best Time to Buy and Sell Stock | Easy | Array, Dynamic Programming |
| 70 | Climbing Stairs | Easy | Memoization, Math, Dynamic Programming |
| 53 | Maximum Subarray | Medium | Array, Divide and Conquer, Dynamic Programming |
| 416 | Partition Equal Subset Sum | Medium | Array, Dynamic Programming |
| 62 | Unique Paths | Medium | Math, Dynamic Programming, Combinatorics |
Two Pointers (5)
| # | Problem | Difficulty | Topics |
|---|---|---|---|
| 125 | Valid Palindrome | Easy | Two Pointers, String |
| 15 | 3Sum | Medium | Array, Two Pointers, Sorting |
| 75 | Sort Colors | Medium | Array, Two Pointers, Sorting |
| 5 | Longest Palindromic Substring | Medium | Two Pointers, String, Dynamic Programming |
| 11 | Container With Most Water | Medium | Greedy, Array, Two Pointers |
Tree Traversal (12)
| # | Problem | Difficulty | Topics |
|---|---|---|---|
| 226 | Invert Binary Tree | Easy | Tree, Depth-First Search, Breadth-First Search +1 |
| 235 | Lowest Common Ancestor of a Binary Search Tree | Medium | Tree, Depth-First Search, Binary Search Tree +1 |
| 110 | Balanced Binary Tree | Easy | Tree, Depth-First Search, Binary Tree |
| 543 | Diameter of Binary Tree | Easy | Tree, Depth-First Search, Binary Tree |
| 104 | Maximum Depth of Binary Tree | Easy | Tree, Depth-First Search, Breadth-First Search +1 |
| 102 | Binary Tree Level Order Traversal | Medium | Tree, Breadth-First Search, Binary Tree |
| 98 | Validate Binary Search Tree | Medium | Tree, Depth-First Search, Binary Search Tree +1 |
| 236 | Lowest Common Ancestor of a Binary Tree | Medium | Tree, Depth-First Search, Binary Tree |
| 199 | Binary Tree Right Side View | Medium | Tree, Depth-First Search, Breadth-First Search +1 |
| 105 | Construct Binary Tree from Preorder and Inorder Traversal | Medium | Tree, Array, Hash Table +2 |
| 230 | Kth Smallest Element in a BST | Medium | Tree, Depth-First Search, Binary Search Tree +1 |
| 297 | Serialize and Deserialize Binary Tree | Hard | Tree, Depth-First Search, Breadth-First Search +3 |
Sorting (4)
| # | Problem | Difficulty | Topics |
|---|---|---|---|
| 242 | Valid Anagram | Easy | Hash Table, String, Sorting |
| 169 | Majority Element | Easy | Array, Hash Table, Divide and Conquer +2 |
| 217 | Contains Duplicate | Easy | Array, Hash Table, Sorting |
| 56 | Merge Intervals | Medium | Array, Sorting |
Monotonic Stack (4)
| # | Problem | Difficulty | Topics |
|---|---|---|---|
| 704 | Binary Search | Easy | Array, Binary Search |
| 278 | First Bad Version | Easy | Binary Search, Interactive |
| 33 | Search in Rotated Sorted Array | Medium | Array, Binary Search |
| 1235 | Maximum Profit in Job Scheduling | Hard | Array, Binary Search, Dynamic Programming +1 |
Matrix and Grid (4)
| # | Problem | Difficulty | Topics |
|---|---|---|---|
| 733 | Flood Fill | Easy | Depth-First Search, Breadth-First Search, Array +1 |
| 542 | 01 Matrix | Medium | Breadth-First Search, Array, Dynamic Programming +1 |
| 994 | Rotting Oranges | Medium | Breadth-First Search, Array, Matrix |
| 54 | Spiral Matrix | Medium | Array, Matrix, Simulation |
Greedy (1)
| # | Problem | Difficulty | Topics |
|---|---|---|---|
| 409 | Longest Palindrome | Easy | Greedy, Hash Table, String |
Bit Manipulation (1)
| # | Problem | Difficulty | Topics |
|---|---|---|---|
| 67 | Add Binary | Easy | Bit Manipulation, Math, String +1 |
Other (1)
| # | Problem | Difficulty | Topics |
|---|---|---|---|
| 57 | Insert Interval | Medium | Array |
Heap / Priority Queue (3)
| # | Problem | Difficulty | Topics |
|---|---|---|---|
| 973 | K Closest Points to Origin | Medium | Geometry, Array, Math +4 |
| 621 | Task Scheduler | Medium | Greedy, Array, Hash Table +3 |
| 295 | Find Median from Data Stream | Hard | Design, Two Pointers, Data Stream +2 |
Sliding Window (3)
| # | Problem | Difficulty | Topics |
|---|---|---|---|
| 3 | Longest Substring Without Repeating Characters | Medium | Hash Table, String, Sliding Window |
| 438 | Find All Anagrams in a String | Medium | Hash Table, String, Sliding Window |
| 76 | Minimum Window Substring | Hard | Hash Table, String, Sliding Window |
Breadth-First Search (3)
| # | Problem | Difficulty | Topics |
|---|---|---|---|
| 133 | Clone Graph | Medium | Depth-First Search, Breadth-First Search, Graph +1 |
| 322 | Coin Change | Medium | Breadth-First Search, Array, Dynamic Programming |
| 127 | Word Ladder | Hard | Breadth-First Search, Hash Table, String |
Topological Sort (2)
| # | Problem | Difficulty | Topics |
|---|---|---|---|
| 207 | Course Schedule | Medium | Depth-First Search, Breadth-First Search, Graph +1 |
| 310 | Minimum Height Trees | Medium | Depth-First Search, Breadth-First Search, Graph +1 |
Trie (2)
| # | Problem | Difficulty | Topics |
|---|---|---|---|
| 208 | Implement Trie (Prefix Tree) | Medium | Design, Trie, Hash Table +1 |
| 139 | Word Break | Medium | Trie, Memoization, Array +3 |
Prefix Sum (1)
| # | Problem | Difficulty | Topics |
|---|---|---|---|
| 238 | Product of Array Except Self | Medium | Array, Prefix Sum |
Union-Find (2)
| # | Problem | Difficulty | Topics |
|---|---|---|---|
| 200 | Number of Islands | Medium | Depth-First Search, Breadth-First Search, Union Find +2 |
| 721 | Accounts Merge | Medium | Depth-First Search, Breadth-First Search, Union Find +4 |
Backtracking (5)
| # | Problem | Difficulty | Topics |
|---|---|---|---|
| 39 | Combination Sum | Medium | Array, Backtracking |
| 46 | Permutations | Medium | Array, Backtracking |
| 78 | Subsets | Medium | Bit Manipulation, Array, Backtracking |
| 17 | Letter Combinations of a Phone Number | Medium | Hash Table, String, Backtracking |
| 79 | Word Search | Medium | Depth-First Search, Array, String +2 |
Binary Search (1)
| # | Problem | Difficulty | Topics |
|---|---|---|---|
| 981 | Time Based Key-Value Store | Medium | Design, Hash Table, String +1 |
Other study lists
Blind 7575 problemsThe Blind 75: a 75-problem list assembled from the patterns that keep reappearing in technical interviews, grouped by topic. Every entry links to a Python solution with complexity analysis.NeetCode 150150 problemsThe NeetCode 150: an expansion of the Blind 75 into eighteen topic groups, from arrays and hashing through advanced graphs and two-dimensional dynamic programming.LeetCode 7575 problemsLeetCode 75: the official study plan, seventy-five problems across twenty-two topic groups from array and string work up to monotonic stacks. Skewed easier than the Blind 75 and better as a first pass.Top Interview 150150 problemsTop Interview 150: the official interview-preparation list, a hundred and fifty problems covering every data structure and technique a technical screen is likely to reach for.
Or go by technique instead of by list: all LeetCode patterns · the full problem list.
The Grind 75 does not cover the problem you get asked
Stealth Interview is a desktop app for macOS and Windows. It reads the coding problem off your screen, returns a working solution with a step-by-step explanation and its time and space complexity, and transcribes what the interviewer is saying — while staying invisible to screen sharing.