🏗️ NeetCode 150 — SRS

Kotlin
⭐ Critical (58) 📋 Active (129) 📚 All (150) 58 critical · 71 optional · 21 skip
⭐ critical — high frequency, must know ○ optional — good to know, lower priority — skip — rarely appears outside FAANG
150Total
0Due
0Done
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📋 Due Now (150)

#1 ⭐ Contains Duplicate LC [E] New
#2 ⭐ Valid Anagram LC [E] New
#3 ⭐ Two Sum LC [E] New
#4 ⭐ Group Anagrams LC [M] New
#5 ⭐ Top K Frequent Elements LC [M] New
#6 ○ Encode and Decode Strings LC [M] New
#7 ⭐ Product of Array Except Self LC [M] New
#8 ○ Valid Sudoku LC [M] New
#9 ○ Longest Consecutive Sequence LC [M] New
#10 ⭐ Valid Palindrome LC [E] New
#11 ⭐ Two Sum II Input Array Is Sorted LC [M] New
#12 ⭐ 3Sum LC [M] New
#13 ⭐ Container With Most Water LC [M] New
#14 ○ Trapping Rain Water LC [H] New
#15 ⭐ Best Time to Buy And Sell Stock LC [E] New
#16 ⭐ Longest Substring Without Repeating Characters LC [M] New
#17 ⭐ Longest Repeating Character Replacement LC [M] New
#18 ⭐ Permutation In String LC [M] New
#19 ○ Minimum Window Substring LC [H] New
#20 ○ Sliding Window Maximum LC [H] New
#21 ⭐ Valid Parentheses LC [E] New
#22 ⭐ Min Stack LC [M] New
#23 ○ Evaluate Reverse Polish Notation LC [M] New
#24 ⭐ Daily Temperatures LC [M] New
#25 ○ Car Fleet LC [M] New
#26 ○ Largest Rectangle In Histogram LC [H] New
#27 ⭐ Binary Search LC [E] New
#28 ⭐ Search a 2D Matrix LC [M] New
#29 ○ Koko Eating Bananas LC [M] New
#30 ⭐ Find Minimum In Rotated Sorted Array LC [M] New
#31 ⭐ Search In Rotated Sorted Array LC [M] New
#32 ○ Time Based Key Value Store LC [M] New
#33 ○ Median of Two Sorted Arrays LC [H] New
#34 ⭐ Reverse Linked List LC [E] New
#35 ⭐ Merge Two Sorted Lists LC [E] New
#36 ⭐ Linked List Cycle LC [E] New
#37 ⭐ Reorder List LC [M] New
#38 ⭐ Remove Nth Node From End of List LC [M] New
#39 ○ Copy List With Random Pointer LC [M] New
#40 ⭐ Add Two Numbers LC [M] New
#41 ○ Find The Duplicate Number LC [M] New
#42 ⭐ LRU Cache LC [M] New
#43 ○ Merge K Sorted Lists LC [H] New
#44 — Reverse Nodes In K Group LC [H] New
#45 ⭐ Invert Binary Tree LC [E] New
#46 ⭐ Maximum Depth of Binary Tree LC [E] New
#47 ⭐ Diameter of Binary Tree LC [E] New
#48 ○ Balanced Binary Tree LC [E] New
#49 ○ Same Tree LC [E] New
#50 ○ Subtree of Another Tree LC [E] New
#51 ⭐ Lowest Common Ancestor of a Binary Search Tree LC [M] New
#52 ⭐ Binary Tree Level Order Traversal LC [M] New
#53 ○ Binary Tree Right Side View LC [M] New
#54 ○ Count Good Nodes In Binary Tree LC [M] New
#55 ⭐ Validate Binary Search Tree LC [M] New
#56 ○ Kth Smallest Element In a Bst LC [M] New
#57 ○ Construct Binary Tree From Preorder And Inorder Traversal LC [M] New
#58 ○ Binary Tree Maximum Path Sum LC [H] New
#59 ○ Serialize And Deserialize Binary Tree LC [H] New
#60 ○ Kth Largest Element In a Stream LC [E] New
#61 ○ Last Stone Weight LC [E] New
#62 ⭐ K Closest Points to Origin LC [M] New
#63 ⭐ Kth Largest Element In An Array LC [M] New
#64 ○ Task Scheduler LC [M] New
#65 ○ Design Twitter LC [M] New
#66 ○ Find Median From Data Stream LC [H] New
#67 ⭐ Subsets LC [M] New
#68 ⭐ Combination Sum LC [M] New
#69 ○ Combination Sum II LC [M] New
#70 ⭐ Permutations LC [M] New
#71 ○ Subsets II LC [M] New
#72 ⭐ Generate Parentheses LC [M] New
#73 ⭐ Word Search LC [M] New
#74 ○ Palindrome Partitioning LC [M] New
#75 ○ Letter Combinations of a Phone Number LC [M] New
#76 ○ N Queens LC [H] New
#77 ⭐ Implement Trie Prefix Tree LC [M] New
#78 ○ Design Add And Search Words Data Structure LC [M] New
#79 — Word Search II LC [H] New
#80 ⭐ Number of Islands LC [M] New
#81 ○ Max Area of Island LC [M] New
#82 ⭐ Clone Graph LC [M] New
#83 ○ Walls And Gates LC [M] New
#84 ⭐ Rotting Oranges LC [M] New
#85 ○ Pacific Atlantic Water Flow LC [M] New
#86 ○ Surrounded Regions LC [M] New
#87 ⭐ Course Schedule LC [M] New
#88 ○ Course Schedule II LC [M] New
#89 ○ Graph Valid Tree LC [M] New
#90 ○ Number of Connected Components In An Undirected Graph LC [M] New
#91 ○ Redundant Connection LC [M] New
#92 — Word Ladder LC [H] New
#93 — Network Delay Time LC [M] New
#94 — Reconstruct Itinerary LC [H] New
#95 — Min Cost to Connect All Points LC [M] New
#96 — Swim In Rising Water LC [H] New
#97 — Alien Dictionary LC [H] New
#98 — Cheapest Flights Within K Stops LC [M] New
#99 ⭐ Climbing Stairs LC [E] New
#100 ○ Min Cost Climbing Stairs LC [E] New
#101 ⭐ House Robber LC [M] New
#102 ○ House Robber II LC [M] New
#103 ○ Longest Palindromic Substring LC [M] New
#104 ○ Palindromic Substrings LC [M] New
#105 ○ Decode Ways LC [M] New
#106 ⭐ Coin Change LC [M] New
#107 ○ Maximum Product Subarray LC [M] New
#108 ⭐ Word Break LC [M] New
#109 ○ Longest Increasing Subsequence LC [M] New
#110 ○ Partition Equal Subset Sum LC [M] New
#111 ⭐ Unique Paths LC [M] New
#112 ⭐ Longest Common Subsequence LC [M] New
#113 ○ Best Time to Buy And Sell Stock With Cooldown LC [M] New
#114 ○ Coin Change II LC [M] New
#115 ○ Target Sum LC [M] New
#116 ○ Interleaving String LC [M] New
#117 — Longest Increasing Path In a Matrix LC [H] New
#118 — Distinct Subsequences LC [H] New
#119 ○ Edit Distance LC [M] New
#120 — Burst Balloons LC [H] New
#121 — Regular Expression Matching LC [H] New
#122 ⭐ Maximum Subarray LC [M] New
#123 ○ Jump Game LC [M] New
#124 ○ Jump Game II LC [M] New
#125 ○ Gas Station LC [M] New
#126 ○ Hand of Straights LC [M] New
#127 ○ Merge Triplets to Form Target Triplet LC [M] New
#128 ○ Partition Labels LC [M] New
#129 ○ Valid Parenthesis String LC [M] New
#130 ⭐ Insert Interval LC [M] New
#131 ⭐ Merge Intervals LC [M] New
#132 ○ Non Overlapping Intervals LC [M] New
#133 ○ Meeting Rooms LC [E] New
#134 ⭐ Meeting Rooms II LC [M] New
#135 — Minimum Interval to Include Each Query LC [H] New
#136 ⭐ Rotate Image LC [M] New
#137 ⭐ Spiral Matrix LC [M] New
#138 ○ Set Matrix Zeroes LC [M] New
#139 ○ Happy Number LC [E] New
#140 ○ Plus One LC [E] New
#141 ○ Pow(x, n) LC [M] New
#142 ○ Multiply Strings LC [M] New
#143 ○ Detect Squares LC [M] New
#144 — Single Number LC [E] New
#145 — Number of 1 Bits LC [E] New
#146 — Counting Bits LC [E] New
#147 — Reverse Bits LC [E] New
#148 — Missing Number LC [E] New
#149 — Sum of Two Integers LC [M] New
#150 — Reverse Integer LC [M] New

📚 Problems

Arrays & Hashing (9)

#1 ⭐ Contains Duplicate LC [E] New
#2 ⭐ Valid Anagram LC [E] New
#3 ⭐ Two Sum LC [E] New
#4 ⭐ Group Anagrams LC [M] New
#5 ⭐ Top K Frequent Elements LC [M] New
#6 ○ Encode and Decode Strings LC [M] New
#7 ⭐ Product of Array Except Self LC [M] New
#8 ○ Valid Sudoku LC [M] New
#9 ○ Longest Consecutive Sequence LC [M] New

Two Pointers (5)

#10 ⭐ Valid Palindrome LC [E] New
#11 ⭐ Two Sum II Input Array Is Sorted LC [M] New
#12 ⭐ 3Sum LC [M] New
#13 ⭐ Container With Most Water LC [M] New
#14 ○ Trapping Rain Water LC [H] New

Sliding Window (6)

#15 ⭐ Best Time to Buy And Sell Stock LC [E] New
#16 ⭐ Longest Substring Without Repeating Characters LC [M] New
#17 ⭐ Longest Repeating Character Replacement LC [M] New
#18 ⭐ Permutation In String LC [M] New
#19 ○ Minimum Window Substring LC [H] New
#20 ○ Sliding Window Maximum LC [H] New

Stack (6)

#21 ⭐ Valid Parentheses LC [E] New
#22 ⭐ Min Stack LC [M] New
#23 ○ Evaluate Reverse Polish Notation LC [M] New
#24 ⭐ Daily Temperatures LC [M] New
#25 ○ Car Fleet LC [M] New
#26 ○ Largest Rectangle In Histogram LC [H] New

Binary Search (7)

#27 ⭐ Binary Search LC [E] New
#28 ⭐ Search a 2D Matrix LC [M] New
#29 ○ Koko Eating Bananas LC [M] New
#30 ⭐ Find Minimum In Rotated Sorted Array LC [M] New
#31 ⭐ Search In Rotated Sorted Array LC [M] New
#32 ○ Time Based Key Value Store LC [M] New
#33 ○ Median of Two Sorted Arrays LC [H] New

Linked List (11)

#34 ⭐ Reverse Linked List LC [E] New
#35 ⭐ Merge Two Sorted Lists LC [E] New
#36 ⭐ Linked List Cycle LC [E] New
#37 ⭐ Reorder List LC [M] New
#38 ⭐ Remove Nth Node From End of List LC [M] New
#39 ○ Copy List With Random Pointer LC [M] New
#40 ⭐ Add Two Numbers LC [M] New
#41 ○ Find The Duplicate Number LC [M] New
#42 ⭐ LRU Cache LC [M] New
#43 ○ Merge K Sorted Lists LC [H] New
#44 — Reverse Nodes In K Group LC [H] New

Trees (15)

#45 ⭐ Invert Binary Tree LC [E] New
#46 ⭐ Maximum Depth of Binary Tree LC [E] New
#47 ⭐ Diameter of Binary Tree LC [E] New
#48 ○ Balanced Binary Tree LC [E] New
#49 ○ Same Tree LC [E] New
#50 ○ Subtree of Another Tree LC [E] New
#51 ⭐ Lowest Common Ancestor of a Binary Search Tree LC [M] New
#52 ⭐ Binary Tree Level Order Traversal LC [M] New
#53 ○ Binary Tree Right Side View LC [M] New
#54 ○ Count Good Nodes In Binary Tree LC [M] New
#55 ⭐ Validate Binary Search Tree LC [M] New
#56 ○ Kth Smallest Element In a Bst LC [M] New
#57 ○ Construct Binary Tree From Preorder And Inorder Traversal LC [M] New
#58 ○ Binary Tree Maximum Path Sum LC [H] New
#59 ○ Serialize And Deserialize Binary Tree LC [H] New

Heap / Priority Queue (7)

#60 ○ Kth Largest Element In a Stream LC [E] New
#61 ○ Last Stone Weight LC [E] New
#62 ⭐ K Closest Points to Origin LC [M] New
#63 ⭐ Kth Largest Element In An Array LC [M] New
#64 ○ Task Scheduler LC [M] New
#65 ○ Design Twitter LC [M] New
#66 ○ Find Median From Data Stream LC [H] New

Backtracking (10)

#67 ⭐ Subsets LC [M] New
#68 ⭐ Combination Sum LC [M] New
#69 ○ Combination Sum II LC [M] New
#70 ⭐ Permutations LC [M] New
#71 ○ Subsets II LC [M] New
#72 ⭐ Generate Parentheses LC [M] New
#73 ⭐ Word Search LC [M] New
#74 ○ Palindrome Partitioning LC [M] New
#75 ○ Letter Combinations of a Phone Number LC [M] New
#76 ○ N Queens LC [H] New

Tries (3)

#77 ⭐ Implement Trie Prefix Tree LC [M] New
#78 ○ Design Add And Search Words Data Structure LC [M] New
#79 — Word Search II LC [H] New

Graphs (13)

#80 ⭐ Number of Islands LC [M] New
#81 ○ Max Area of Island LC [M] New
#82 ⭐ Clone Graph LC [M] New
#83 ○ Walls And Gates LC [M] New
#84 ⭐ Rotting Oranges LC [M] New
#85 ○ Pacific Atlantic Water Flow LC [M] New
#86 ○ Surrounded Regions LC [M] New
#87 ⭐ Course Schedule LC [M] New
#88 ○ Course Schedule II LC [M] New
#89 ○ Graph Valid Tree LC [M] New
#90 ○ Number of Connected Components In An Undirected Graph LC [M] New
#91 ○ Redundant Connection LC [M] New
#92 — Word Ladder LC [H] New

Advanced Graphs (6)

#93 — Network Delay Time LC [M] New
#94 — Reconstruct Itinerary LC [H] New
#95 — Min Cost to Connect All Points LC [M] New
#96 — Swim In Rising Water LC [H] New
#97 — Alien Dictionary LC [H] New
#98 — Cheapest Flights Within K Stops LC [M] New

1-D Dynamic Programming (12)

#99 ⭐ Climbing Stairs LC [E] New
#100 ○ Min Cost Climbing Stairs LC [E] New
#101 ⭐ House Robber LC [M] New
#102 ○ House Robber II LC [M] New
#103 ○ Longest Palindromic Substring LC [M] New
#104 ○ Palindromic Substrings LC [M] New
#105 ○ Decode Ways LC [M] New
#106 ⭐ Coin Change LC [M] New
#107 ○ Maximum Product Subarray LC [M] New
#108 ⭐ Word Break LC [M] New
#109 ○ Longest Increasing Subsequence LC [M] New
#110 ○ Partition Equal Subset Sum LC [M] New

2-D Dynamic Programming (11)

#111 ⭐ Unique Paths LC [M] New
#112 ⭐ Longest Common Subsequence LC [M] New
#113 ○ Best Time to Buy And Sell Stock With Cooldown LC [M] New
#114 ○ Coin Change II LC [M] New
#115 ○ Target Sum LC [M] New
#116 ○ Interleaving String LC [M] New
#117 — Longest Increasing Path In a Matrix LC [H] New
#118 — Distinct Subsequences LC [H] New
#119 ○ Edit Distance LC [M] New
#120 — Burst Balloons LC [H] New
#121 — Regular Expression Matching LC [H] New

Greedy (8)

#122 ⭐ Maximum Subarray LC [M] New
#123 ○ Jump Game LC [M] New
#124 ○ Jump Game II LC [M] New
#125 ○ Gas Station LC [M] New
#126 ○ Hand of Straights LC [M] New
#127 ○ Merge Triplets to Form Target Triplet LC [M] New
#128 ○ Partition Labels LC [M] New
#129 ○ Valid Parenthesis String LC [M] New

Intervals (6)

#130 ⭐ Insert Interval LC [M] New
#131 ⭐ Merge Intervals LC [M] New
#132 ○ Non Overlapping Intervals LC [M] New
#133 ○ Meeting Rooms LC [E] New
#134 ⭐ Meeting Rooms II LC [M] New
#135 — Minimum Interval to Include Each Query LC [H] New

Math & Geometry (8)

#136 ⭐ Rotate Image LC [M] New
#137 ⭐ Spiral Matrix LC [M] New
#138 ○ Set Matrix Zeroes LC [M] New
#139 ○ Happy Number LC [E] New
#140 ○ Plus One LC [E] New
#141 ○ Pow(x, n) LC [M] New
#142 ○ Multiply Strings LC [M] New
#143 ○ Detect Squares LC [M] New

Bit Manipulation (7)

#144 — Single Number LC [E] New
#145 — Number of 1 Bits LC [E] New
#146 — Counting Bits LC [E] New
#147 — Reverse Bits LC [E] New
#148 — Missing Number LC [E] New
#149 — Sum of Two Integers LC [M] New
#150 — Reverse Integer LC [M] New