NeetCode 250 LeetCode Study Plan

NeetCode 250 expands NeetCode 150 to 250 problems across the same 18 topics. Each chapter opens with approachable warm-up problems before stepping up to medium and hard interview questions, making the climb smoother if NeetCode 150 jumps too quickly.

All 150 problems from NeetCode 150 are included inside NeetCode 250, and Dokicode syncs your solved problems across every list automatically.

250 problemsRating 1161–286318 Topics

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Arrays and Hashing

Problem	Difficulty / Rating
1929. Concatenation of Array	Easy
217. Contains Duplicate	Easy
242. Valid Anagram	Easy
1. Two Sum	1161
14. Longest Common Prefix	Easy
49. Group Anagrams	Medium
27. Remove Element	1263
169. Majority Element	Easy
705. Design HashSet	Easy
706. Design HashMap	Easy
912. Sort an Array	Medium
75. Sort Colors	1263
347. Top K Frequent Elements	Medium
271. Encode and Decode Strings Premium (Optional)	Medium
304. Range Sum Query 2D Immutable	1484
238. Product of Array Except Self	Medium
36. Valid Sudoku	Medium
128. Longest Consecutive Sequence	Medium
122. Best Time to Buy AND Sell Stock II	Medium
229. Majority Element II	Medium
560. Subarray Sum Equals K	1592
41. First Missing Positive	Hard

Two Pointers

Problem	Difficulty / Rating
344. Reverse String	1263
125. Valid Palindrome	1263
680. Valid Palindrome II	1400
1768. Merge Strings Alternately	Easy
88. Merge Sorted Array	1315
26. Remove Duplicates From Sorted Array	1263
167. Two Sum II Input Array Is Sorted	1263
15. 3sum	1263
18. 4sum	1263
189. Rotate Array	Medium
11. Container with Most Water	1263
881. Boats to Save People	1530
42. Trapping Rain Water	1263

Sliding Window

Problem	Difficulty / Rating
219. Contains Duplicate II	1365
121. Best Time to Buy AND Sell Stock	Easy
3. Longest Substring Without Repeating Characters	1263
424. Longest Repeating Character Replacement	1787
567. Permutation in String	2006
209. Minimum Size Subarray Sum	1263
658. Find K Closest Elements	1263
76. Minimum Window Substring	1592
239. Sliding Window Maximum	1851

Stack

Problem	Difficulty / Rating
682. Baseball Game	1228
20. Valid Parentheses	1242
225. Implement Stack Using Queues	1851
232. Implement Queue Using Stacks	1851
155. Min Stack	1772
150. Evaluate Reverse Polish Notation	1408
22. Generate Parentheses	Medium
735. Asteroid Collision	2057
739. Daily Temperatures	1700
901. Online Stock Span	1709
853. Car Fleet	1600
71. Simplify Path	1578
394. Decode String	1408
895. Maximum Frequency Stack	2028
84. Largest Rectangle in Histogram	1900

Binary Search

Problem	Difficulty / Rating
704. Binary Search	Easy
35. Search Insert Position	Easy
374. Guess Number Higher OR Lower	Easy
69. Sqrtx	Easy
74. Search a 2D Matrix	Medium
875. Koko Eating Bananas	1766
1011. Capacity to Ship Packages Within D Days	1725
153. Find Minimum in Rotated Sorted Array	Medium
33. Search in Rotated Sorted Array	Medium
81. Search in Rotated Sorted Array II	Medium
981. Time Based Key Value Store	Medium
410. Split Array Largest Sum	Hard
4. Median of Two Sorted Arrays	Hard
1095. Find in Mountain Array	1827

Linked Lists

Problem	Difficulty / Rating
206. Reverse Linked List	Easy
21. Merge Two Sorted Lists	Easy
141. Linked List Cycle	Easy
143. Reorder List	Medium
19. Remove Nth Node From End of List	Medium
138. Copy List with Random Pointer	Medium
2. Add Two Numbers	Medium
287. Find the Duplicate Number	Medium
92. Reverse Linked List II	Medium
622. Design Circular Queue	1851
146. Lru Cache	2863
460. Lfu Cache	2863
23. Merge K Sorted Lists	1818
25. Reverse Nodes in K Group	Hard

Trees

Problem	Difficulty / Rating
94. Binary Tree Inorder Traversal	Easy
144. Binary Tree Preorder Traversal	Easy
145. Binary Tree Postorder Traversal	Easy
226. Invert Binary Tree	Easy
104. Maximum Depth of Binary Tree	Easy
543. Diameter of Binary Tree	Easy
110. Balanced Binary Tree	Easy
100. Same Tree	Easy
572. Subtree of Another Tree	Easy
235. Lowest Common Ancestor of a Binary Search Tree	Medium
701. Insert Into a Binary Search Tree	Medium
450. Delete Node in a Bst	Medium
102. Binary Tree Level Order Traversal	Medium
199. Binary Tree Right Side View	Medium
427. Construct Quad Tree	Medium
1448. Count Good Nodes in Binary Tree	1360
98. Validate Binary Search Tree	Medium
230. Kth Smallest Element in a Bst	Medium
105. Construct Binary Tree From Preorder AND Inorder Traversal	Medium
337. House Robber III	Medium
1325. Delete Leaves with a Given Value	1407
124. Binary Tree Maximum Path Sum	Hard
297. Serialize AND Deserialize Binary Tree	Hard

Heaps

Problem	Difficulty / Rating
703. Kth Largest Element in a Stream	1419
1046. Last Stone Weight	1173
973. K Closest Points to Origin	Medium
215. Kth Largest Element in an Array	Medium
621. Task Scheduler	1905
355. Design Twitter	1822
1834. Single Threaded Cpu	1798
767. Reorganize String	1681
1405. Longest Happy String	1821
1094. Car Pooling	1441
295. Find Median From Data Stream	2159
502. Ipo	1822

Backtracking

Problem	Difficulty / Rating
1863. Sum of All Subset XOR Totals	1372
78. Subsets	Medium
39. Combination Sum	Medium
40. Combination Sum II	Medium
77. Combinations	Medium
46. Permutations	Medium
90. Subsets II	Medium
47. Permutations II	Medium
79. Word Search	Medium
131. Palindrome Partitioning	Medium
17. Letter Combinations of a Phone Number	Medium
473. Matchsticks to Square	Medium
698. Partition to K Equal Sum Subsets	Medium
51. N Queens	Hard
52. N Queens II	Hard
140. Word Break II	1725

Tries

Problem	Difficulty / Rating
208. Implement Trie Prefix Tree	1180
211. Design Add AND Search Words Data Structure	1725
2707. Extra Characters in a String	1736
212. Word Search II	1725

Graphs

Problem	Difficulty / Rating
463. Island Perimeter	Easy
953. Verifying an Alien Dictionary	Easy
997. Find the Town Judge	Easy
200. Number of Islands	Medium
695. Max Area of Island	Medium
133. Clone Graph	Medium
286. Walls and Gates Premium (Optional)	Medium
994. Rotting Oranges	Medium
417. Pacific Atlantic Water Flow	1900
130. Surrounded Regions	Medium
752. Open the Lock	1878
207. Course Schedule	Medium
210. Course Schedule II	Medium
261. Graph Valid Tree Premium (Optional)	Medium
1462. Course Schedule IV	Medium
323. Number of Connected Components in an Undirected Graph Premium (Optional)	Medium
684. Redundant Connection	Medium
721. Accounts Merge	Medium
399. Evaluate Division	1725
310. Minimum Height Trees	Medium
127. Word Ladder	Hard

Advanced Graphs

Problem	Difficulty / Rating
1631. Path with Minimum Effort	1948
743. Network Delay Time	Medium
332. Reconstruct Itinerary	Hard
1584. Min Cost to Connect All Points	1858
778. Swim in Rising Water	2097
269. Alien Dictionary Premium (Optional)	Hard
787. Cheapest Flights Within K Stops	Medium
1489. Find Critical AND Pseudo Critical Edges in Minimum Spanning Tree	2572
2392. Build a Matrix with Conditions	1961
2709. Greatest Common Divisor Traversal	2172

1-D DP

Problem	Difficulty / Rating
70. Climbing Stairs	Easy
746. Min Cost Climbing Stairs	1500
1137. N Th Tribonacci Number	Easy
198. House Robber	Medium
213. House Robber II	Medium
5. Longest Palindromic Substring	Medium
647. Palindromic Substrings	Medium
91. Decode Ways	Medium
322. Coin Change	Medium
152. Maximum Product Subarray	Medium
139. Word Break	Medium
300. Longest Increasing Subsequence	Medium
416. Partition Equal Subset Sum	Medium
377. Combination Sum IV	1600
279. Perfect Squares	Medium
343. Integer Break	Medium
1406. Stone Game III	2027

2-D DP

Problem	Difficulty / Rating
62. Unique Paths	Medium
63. Unique Paths II	Medium
64. Minimum Path Sum	Medium
1143. Longest Common Subsequence	Medium
1049. Last Stone Weight II	2092
309. Best Time to Buy AND Sell Stock with Cooldown	Medium
518. Coin Change II	Medium
494. Target Sum	Medium
97. Interleaving String	Medium
877. Stone Game	1590
1140. Stone Game II	2035
329. Longest Increasing Path in a Matrix	Hard
115. Distinct Subsequences	Hard
72. Edit Distance	Medium
312. Burst Balloons	Hard
10. Regular Expression Matching	Hard

Greedy

Problem	Difficulty / Rating
860. Lemonade Change	Easy
53. Maximum Subarray	Medium
918. Maximum Sum Circular Subarray	1777
978. Longest Turbulent Subarray	1393
55. Jump Game	Medium
45. Jump Game II	1700
1871. Jump Game VII	1896
134. Gas Station	Medium
846. Hand of Straights	Medium
649. Dota2 Senate	1686
1899. Merge Triplets to Form Target Triplet	1636
763. Partition Labels	1443
678. Valid Parenthesis String	1700
135. Candy	1263

Intervals

Problem	Difficulty / Rating
57. Insert Interval	Medium
56. Merge Intervals	Medium
435. Non Overlapping Intervals	1700
252. Meeting Rooms Premium (Optional)	Easy
253. Meeting Rooms II Premium (Optional)	Medium
2402. Meeting Rooms III	2093
1851. Minimum Interval to Include Each Query	2286

Math and Geometry

Problem	Difficulty / Rating
168. Excel Sheet Column Title	Easy
1071. Greatest Common Divisor of Strings	1398
2807. Insert Greatest Common Divisors in Linked List	1279
867. Transpose Matrix	Easy
48. Rotate Image	Medium
54. Spiral Matrix	Medium
73. Set Matrix Zeroes	Medium
202. Happy Number	Easy
66. Plus One	Easy
13. Roman to Integer	1209
50. Pow(x, n)	Medium
43. Multiply Strings	Medium
2013. Detect Squares	Medium

Bit Manipulation

Problem	Difficulty / Rating
136. Single Number	Easy
191. Number of 1 Bits	Easy
338. Counting Bits	Easy
67. Add Binary	Easy
190. Reverse Bits	Easy
268. Missing Number	Easy
371. Sum of Two Integers	Medium
7. Reverse Integer	Medium
201. Bitwise AND of Numbers Range	Medium
3133. Minimum Array End	1935

Pick NeetCode 250 for a thorough, unhurried interview preparation schedule, or switch between NeetCode 150 and 250 anytime in the Study Plan drawer.

Ratings come from zerotrac's LeetCode contest ratings. Classic pre-contest problems show their LeetCode difficulty level instead.

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