Pragmatic LeetCode Cheat-Sheet

High-Yield LeetCode ProblemsThe Pragmatic Cheat-Sheet

A curated collection of common technical interview patterns. Optimized for both quick reviews and detailed problem breakdowns.

Browse Problems

Pattern Recognition

Problems are grouped by core algorithmic patterns to help build problem-solving intuition rather than relying on memorization.

Multi-Language Solutions

Compare optimal implementations across multiple languages with clear inline comments to support both fast review and deep dives.

Complexity Analysis and Alternatives

Clear time and space complexity breakdowns and alternative approaches to evaluate algorithmic trade-offs.

1Two SumEasyEArray / String 3Longest Substring Without Repeating CharactersMediumMArray / String 11Container With Most WaterMediumMTwo Pointers 153SumMediumMArray / String 17Letter Combinations of a Phone NumberMediumMBacktracking 19Remove Nth Node From End of ListMediumMLinked List 39Combination SumMediumMBacktracking 42Trapping Rain WaterHardHArray / String 62Unique PathsMediumMDP - Multidimensional 72Edit DistanceMediumMDP - Multidimensional 76Minimum Window SubstringHardHArray / String 104Maximum Depth of Binary TreeEasyEBinary Tree - DFS 136Single NumberEasyEBit Manipulation 138Copy List with Random PointerMediumMLinked List 139Word BreakMediumMDP - 1D 141Linked List CycleEasyELinked List 151Reverse Words in a StringMediumMArray / String 155Min StackMediumMStack 162Find Peak ElementMediumMBinary Search 198House RobberMediumMDP - 1D 199Binary Tree Right Side ViewMediumMBinary Tree - BFS 200Number of IslandsMediumMGraphs - BFS 206Reverse Linked ListEasyELinked List 208Implement Trie (Prefix Tree)MediumMTrie 215Kth Largest Element in an ArrayMediumMHeap / Priority Queue