> ## Documentation Index
> Fetch the complete documentation index at: https://leetcode-py.wisl.dev/llms.txt
> Use this file to discover all available pages before exploring further.

> ## Agent Instructions
> leetcode-py is a Python LeetCode practice environment generator with one CLI: lcpy. It is not a service or platform.
> Each problem is a directory under leetcode/ with README.md, solution.py, test_solution.py, helpers.py, and playground.ipynb. lcpy gen creates them from JSON templates bundled with the package.
> Examples are backed by tests; copy them verbatim.

# Grind 75 in Python with Tested Solutions

> All 75 problems in the Grind 75 list: each generates a tested Python practice environment with a pytest suite and reference solutions.

Grind 75 holds 75 problems (23 Easy, 43 Medium, 9 Hard).
Grind 75 is the essential-75 list from Tech Interview Handbook, ordered by a week-by-week study plan built around pattern coverage and time budget. Every problem generates a Python practice environment with a parametrized pytest suite and a tested reference solution.

Generate the whole collection into the current directory:

```bash theme={"theme":{"light":"github-light","dark":"github-dark"}}
lcpy gen -t grind-75
```

| # | Problem | Difficulty | Solution |
| - | - | - | - |
| 1 | [Two Sum](https://leetcode-py.wisl.dev/problems/two-sum) | Easy | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/two_sum/solution.py) |
| 3 | [Longest Substring Without Repeating Characters](https://leetcode-py.wisl.dev/problems/longest-substring-without-repeating-characters) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/longest_substring_without_repeating_characters/solution.py) |
| 5 | [Longest Palindromic Substring](https://leetcode-py.wisl.dev/problems/longest-palindromic-substring) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/longest_palindromic_substring/solution.py) |
| 8 | [String to Integer (atoi)](https://leetcode-py.wisl.dev/problems/string-to-integer-atoi) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/string_to_integer_atoi/solution.py) |
| 11 | [Container With Most Water](https://leetcode-py.wisl.dev/problems/container-with-most-water) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/container_with_most_water/solution.py) |
| 15 | [3Sum](https://leetcode-py.wisl.dev/problems/three-sum) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/three_sum/solution.py) |
| 17 | [Letter Combinations of a Phone Number](https://leetcode-py.wisl.dev/problems/letter-combinations-of-a-phone-number) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/letter_combinations_of_a_phone_number/solution.py) |
| 20 | [Valid Parentheses](https://leetcode-py.wisl.dev/problems/valid-parentheses) | Easy | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/valid_parentheses/solution.py) |
| 21 | [Merge Two Sorted Lists](https://leetcode-py.wisl.dev/problems/merge-two-sorted-lists) | Easy | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/merge_two_sorted_lists/solution.py) |
| 23 | [Merge k Sorted Lists](https://leetcode-py.wisl.dev/problems/merge-k-sorted-lists) | Hard | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/merge_k_sorted_lists/solution.py) |
| 33 | [Search in Rotated Sorted Array](https://leetcode-py.wisl.dev/problems/search-in-rotated-sorted-array) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/search_in_rotated_sorted_array/solution.py) |
| 39 | [Combination Sum](https://leetcode-py.wisl.dev/problems/combination-sum) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/combination_sum/solution.py) |
| 42 | [Trapping Rain Water](https://leetcode-py.wisl.dev/problems/trapping-rain-water) | Hard | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/trapping_rain_water/solution.py) |
| 46 | [Permutations](https://leetcode-py.wisl.dev/problems/permutations) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/permutations/solution.py) |
| 53 | [Maximum Subarray](https://leetcode-py.wisl.dev/problems/maximum-subarray) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/maximum_subarray/solution.py) |
| 54 | [Spiral Matrix](https://leetcode-py.wisl.dev/problems/spiral-matrix) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/spiral_matrix/solution.py) |
| 56 | [Merge Intervals](https://leetcode-py.wisl.dev/problems/merge-intervals) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/merge_intervals/solution.py) |
| 57 | [Insert Interval](https://leetcode-py.wisl.dev/problems/insert-interval) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/insert_interval/solution.py) |
| 62 | [Unique Paths](https://leetcode-py.wisl.dev/problems/unique-paths) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/unique_paths/solution.py) |
| 67 | [Add Binary](https://leetcode-py.wisl.dev/problems/add-binary) | Easy | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/add_binary/solution.py) |
| 70 | [Climbing Stairs](https://leetcode-py.wisl.dev/problems/climbing-stairs) | Easy | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/climbing_stairs/solution.py) |
| 75 | [Sort Colors](https://leetcode-py.wisl.dev/problems/sort-colors) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/sort_colors/solution.py) |
| 76 | [Minimum Window Substring](https://leetcode-py.wisl.dev/problems/minimum-window-substring) | Hard | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/minimum_window_substring/solution.py) |
| 78 | [Subsets](https://leetcode-py.wisl.dev/problems/subsets) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/subsets/solution.py) |
| 79 | [Word Search](https://leetcode-py.wisl.dev/problems/word-search) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/word_search/solution.py) |
| 84 | [Largest Rectangle in Histogram](https://leetcode-py.wisl.dev/problems/largest-rectangle-in-histogram) | Hard | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/largest_rectangle_in_histogram/solution.py) |
| 98 | [Validate Binary Search Tree](https://leetcode-py.wisl.dev/problems/validate-binary-search-tree) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/validate_binary_search_tree/solution.py) |
| 102 | [Binary Tree Level Order Traversal](https://leetcode-py.wisl.dev/problems/binary-tree-level-order-traversal) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/binary_tree_level_order_traversal/solution.py) |
| 104 | [Maximum Depth of Binary Tree](https://leetcode-py.wisl.dev/problems/maximum-depth-of-binary-tree) | Easy | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/maximum_depth_of_binary_tree/solution.py) |
| 105 | [Construct Binary Tree from Preorder and Inorder Traversal](https://leetcode-py.wisl.dev/problems/construct-binary-tree-from-preorder-and-inorder-traversal) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/construct_binary_tree_from_preorder_and_inorder_traversal/solution.py) |
| 110 | [Balanced Binary Tree](https://leetcode-py.wisl.dev/problems/balanced-binary-tree) | Easy | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/balanced_binary_tree/solution.py) |
| 121 | [Best Time to Buy and Sell Stock](https://leetcode-py.wisl.dev/problems/best-time-to-buy-and-sell-stock) | Easy | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/best_time_to_buy_and_sell_stock/solution.py) |
| 125 | [Valid Palindrome](https://leetcode-py.wisl.dev/problems/valid-palindrome) | Easy | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/valid_palindrome/solution.py) |
| 127 | [Word Ladder](https://leetcode-py.wisl.dev/problems/word-ladder) | Hard | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/word_ladder/solution.py) |
| 133 | [Clone Graph](https://leetcode-py.wisl.dev/problems/clone-graph) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/clone_graph/solution.py) |
| 139 | [Word Break](https://leetcode-py.wisl.dev/problems/word-break) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/word_break/solution.py) |
| 141 | [Linked List Cycle](https://leetcode-py.wisl.dev/problems/linked-list-cycle) | Easy | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/linked_list_cycle/solution.py) |
| 146 | [LRU Cache](https://leetcode-py.wisl.dev/problems/lru-cache) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/lru_cache/solution.py) |
| 150 | [Evaluate Reverse Polish Notation](https://leetcode-py.wisl.dev/problems/evaluate-reverse-polish-notation) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/evaluate_reverse_polish_notation/solution.py) |
| 155 | [Min Stack](https://leetcode-py.wisl.dev/problems/min-stack) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/min_stack/solution.py) |
| 169 | [Majority Element](https://leetcode-py.wisl.dev/problems/majority-element) | Easy | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/majority_element/solution.py) |
| 199 | [Binary Tree Right Side View](https://leetcode-py.wisl.dev/problems/binary-tree-right-side-view) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/binary_tree_right_side_view/solution.py) |
| 200 | [Number of Islands](https://leetcode-py.wisl.dev/problems/number-of-islands) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/number_of_islands/solution.py) |
| 206 | [Reverse Linked List](https://leetcode-py.wisl.dev/problems/reverse-linked-list) | Easy | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/reverse_linked_list/solution.py) |
| 207 | [Course Schedule](https://leetcode-py.wisl.dev/problems/course-schedule) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/course_schedule/solution.py) |
| 208 | [Implement Trie (Prefix Tree)](https://leetcode-py.wisl.dev/problems/implement-trie-prefix-tree) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/implement_trie_prefix_tree/solution.py) |
| 217 | [Contains Duplicate](https://leetcode-py.wisl.dev/problems/contains-duplicate) | Easy | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/contains_duplicate/solution.py) |
| 224 | [Basic Calculator](https://leetcode-py.wisl.dev/problems/basic-calculator) | Hard | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/basic_calculator/solution.py) |
| 226 | [Invert Binary Tree](https://leetcode-py.wisl.dev/problems/invert-binary-tree) | Easy | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/invert_binary_tree/solution.py) |
| 230 | [Kth Smallest Element in a BST](https://leetcode-py.wisl.dev/problems/kth-smallest-element-in-a-bst) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/kth_smallest_element_in_a_bst/solution.py) |
| 232 | [Implement Queue using Stacks](https://leetcode-py.wisl.dev/problems/implement-queue-using-stacks) | Easy | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/implement_queue_using_stacks/solution.py) |
| 235 | [Lowest Common Ancestor of a Binary Search Tree](https://leetcode-py.wisl.dev/problems/lowest-common-ancestor-of-a-binary-search-tree) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/lowest_common_ancestor_of_a_binary_search_tree/solution.py) |
| 236 | [Lowest Common Ancestor of a Binary Tree](https://leetcode-py.wisl.dev/problems/lowest-common-ancestor-of-a-binary-tree) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/lowest_common_ancestor_of_a_binary_tree/solution.py) |
| 238 | [Product of Array Except Self](https://leetcode-py.wisl.dev/problems/product-of-array-except-self) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/product_of_array_except_self/solution.py) |
| 242 | [Valid Anagram](https://leetcode-py.wisl.dev/problems/valid-anagram) | Easy | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/valid_anagram/solution.py) |
| 278 | [First Bad Version](https://leetcode-py.wisl.dev/problems/first-bad-version) | Easy | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/first_bad_version/solution.py) |
| 295 | [Find Median from Data Stream](https://leetcode-py.wisl.dev/problems/find-median-from-data-stream) | Hard | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/find_median_from_data_stream/solution.py) |
| 297 | [Serialize and Deserialize Binary Tree](https://leetcode-py.wisl.dev/problems/serialize-and-deserialize-binary-tree) | Hard | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/serialize_and_deserialize_binary_tree/solution.py) |
| 310 | [Minimum Height Trees](https://leetcode-py.wisl.dev/problems/minimum-height-trees) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/minimum_height_trees/solution.py) |
| 322 | [Coin Change](https://leetcode-py.wisl.dev/problems/coin-change) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/coin_change/solution.py) |
| 383 | [Ransom Note](https://leetcode-py.wisl.dev/problems/ransom-note) | Easy | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/ransom_note/solution.py) |
| 409 | [Longest Palindrome](https://leetcode-py.wisl.dev/problems/longest-palindrome) | Easy | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/longest_palindrome/solution.py) |
| 416 | [Partition Equal Subset Sum](https://leetcode-py.wisl.dev/problems/partition-equal-subset-sum) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/partition_equal_subset_sum/solution.py) |
| 438 | [Find All Anagrams in a String](https://leetcode-py.wisl.dev/problems/find-all-anagrams-in-a-string) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/find_all_anagrams_in_a_string/solution.py) |
| 542 | [01 Matrix](https://leetcode-py.wisl.dev/problems/zero-one-matrix) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/zero_one_matrix/solution.py) |
| 543 | [Diameter of Binary Tree](https://leetcode-py.wisl.dev/problems/diameter-of-binary-tree) | Easy | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/diameter_of_binary_tree/solution.py) |
| 621 | [Task Scheduler](https://leetcode-py.wisl.dev/problems/task-scheduler) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/task_scheduler/solution.py) |
| 704 | [Binary Search](https://leetcode-py.wisl.dev/problems/binary-search) | Easy | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/binary_search/solution.py) |
| 721 | [Accounts Merge](https://leetcode-py.wisl.dev/problems/accounts-merge) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/accounts_merge/solution.py) |
| 733 | [Flood Fill](https://leetcode-py.wisl.dev/problems/flood-fill) | Easy | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/flood_fill/solution.py) |
| 876 | [Middle of the Linked List](https://leetcode-py.wisl.dev/problems/middle-of-the-linked-list) | Easy | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/middle_of_the_linked_list/solution.py) |
| 973 | [K Closest Points to Origin](https://leetcode-py.wisl.dev/problems/k-closest-points-to-origin) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/k_closest_points_to_origin/solution.py) |
| 981 | [Time Based Key-Value Store](https://leetcode-py.wisl.dev/problems/time-based-key-value-store) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/time_based_key_value_store/solution.py) |
| 994 | [Rotting Oranges](https://leetcode-py.wisl.dev/problems/rotting-oranges) | Medium | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/rotting_oranges/solution.py) |
| 1235 | [Maximum Profit in Job Scheduling](https://leetcode-py.wisl.dev/problems/maximum-profit-in-job-scheduling) | Hard | [solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/maximum_profit_in_job_scheduling/solution.py) |


This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.