Roadmap

Saved locally

A pattern-by-pattern path through the curated lists. Each phase pairs a short primer with the problems that drill it — work top to bottom and you cover every core pattern in order. Pick a pace and follow the day-by-day plan, or browse by pattern. Your attempts are tracked on this device.

Pace

Problems

75

Patterns

14

Plan at 3/day

25 days

Calendar

~4 weeks

Attempted 0 of 750%

Week 1

Day 1Arrays & Hashing

ReadArrays & Hashing12m Strings12m Prefix Sums & Difference Arrays11m Sorting13m

1Two SumEasy 217Contains DuplicateEasy 242Valid AnagramEasy

Day 2

252Meeting RoomsEasy 49Group AnagramsMedium 56Merge IntervalsMedium

Day 3Two Pointers

ReadTwo Pointers9m

57Insert IntervalMedium 238Product of Array Except SelfMedium 125Valid PalindromeEasy

Day 4

5Longest Palindromic SubstringMedium 11Container With Most WaterMedium 153SumMedium

Day 5Sliding Window

ReadSliding Window11m

647Palindromic SubstringsMedium 3Longest Substring Without Repeating CharactersMedium 424Longest Repeating Character ReplacementMedium

Day 6Stack & Monotonic Stack

ReadStacks & Queues11m

76Minimum Window SubstringHard 20Valid ParenthesesEasy 143Reorder ListMedium

Day 7Binary Search

ReadBinary Search12m

33Search in Rotated Sorted ArrayMedium 153Find Minimum in Rotated Sorted ArrayMedium 300Longest Increasing SubsequenceMedium

Week 2

Day 8Linked Lists

ReadLinked Lists14m

21Merge Two Sorted ListsEasy 141Linked List CycleEasy 206Reverse Linked ListEasy

Day 9Trees & BST

ReadTrees & Traversals18m

19Remove Nth Node From End of ListMedium 100Same TreeEasy 104Maximum Depth of Binary TreeEasy

Day 10

226Invert Binary TreeEasy 572Subtree of Another TreeEasy 98Validate Binary Search TreeMedium

Day 11

102Binary Tree Level Order TraversalMedium 105Construct Binary Tree from Preorder and Inorder TraversalMedium 230Kth Smallest Element in a BSTMedium

Day 12Tries

ReadTries (Prefix Trees)10m

235Lowest Common Ancestor of a Binary Search TreeMedium 124Binary Tree Maximum Path SumHard 139Word BreakMedium

Day 13

208Implement Trie (Prefix Tree)read-onlyMedium 211Design Add and Search Words Data Structureread-onlyMedium 212Word Search IIHard

Day 14Heaps & Priority Queues

ReadHeaps & Priority Queues13m

253Meeting Rooms IIMedium 347Top K Frequent Elementsread-onlyMedium 23Merge k Sorted ListsHard

Week 3

Day 15BacktrackingGraphs

ReadBacktracking14m

ReadGraphs16m Union–Find (DSU)12m

39Combination Sumread-onlyMedium 79Word SearchMedium 48Rotate ImageMedium

Day 16

54Spiral MatrixMedium 73Set Matrix ZeroesMedium 128Longest Consecutive SequenceMedium

Day 17

133Clone Graphread-onlyMedium 200Number of IslandsMedium 207Course Scheduleread-onlyMedium

Day 18

261Graph Valid TreeMedium 323Number of Connected Components in an Undirected Graphread-onlyMedium 417Pacific Atlantic Water FlowMedium

Day 19Dynamic Programming

Read1-D Dynamic Programming16m 2-D Dynamic Programming17m

269Alien DictionaryHard 70Climbing StairsEasy 121Best Time to Buy and Sell StockEasy

Day 20

53Maximum SubarrayMedium 55Jump GameMedium 62Unique PathsMedium

Day 21

91Decode WaysMedium 152Maximum Product SubarrayMedium 198House RobberMedium

Week 4

Day 22

213House Robber IIMedium 322Coin ChangeMedium 435Non-overlapping IntervalsMedium

Day 23Bit Manipulation

ReadBit Manipulation10m

1143Longest Common Subsequenceread-onlyMedium 190Reverse BitsEasy 191Number of 1 BitsEasy

Day 24

268Missing NumberEasy 338Counting BitsEasy 371Sum of Two IntegersMedium

Day 25Design

ReadDesign (Data Structures)14m

271Encode and Decode Stringsread-onlyMedium 295Find Median from Data Streamread-onlyHard 297Serialize and Deserialize Binary Treeread-onlyHard