Arrays & Strings
Master Two Pointers, Sliding Window, and Prefix Sums. Includes 680 problems.
Study Arrays →Data Structures & Algorithms
Master the core concepts required for software engineering interviews. Clear explanations, cheatsheet formulas, and 3,400+ LeetCode solutions in Java, Python & Python3.
Linked Lists
Pointer manipulation, fast & slow pointers, and cycle detection. Includes 47 problems.
Study Linked Lists →Stacks & Queues
LIFO/FIFO mechanics and the Monotonic Stack pattern. Includes 82 problems.
Study Stacks & Queues →Trees
DFS/BFS traversals, Binary Search Trees, and Heaps. Includes 189 problems.
Study Trees →Graphs
Topological Sort, Shortest Path, Union-Find, BFS & DFS. Includes 301 problems.
Study Graphs →Sorting & Searching
Binary Search variants, Merge Sort, Two Pointers. Includes 414 problems.
Study Sorting →Hash Tables
O(1) lookups, frequency counting, and sliding window. Includes 253 problems.
Study Hash Tables →Dynamic Programming
Memoization, Tabulation, and recognizing DP subproblems. Includes 447 problems.
Study DP →Math & Number Theory
GCD, fast power, prime sieves, modular arithmetic. Includes 369 problems.
Study Math →Greedy Algorithms
Interval scheduling, activity selection, and locally optimal choices. Includes 368 problems.
Study Greedy →Bit Manipulation
XOR tricks, bit masking, and O(1) binary solutions. Includes 74 problems.
Study Bits →Backtracking
Permutations, combinations, N-Queens, Sudoku, and Word Search. Includes 59 problems.
Study Backtracking →Design & Data Structures
LRU/LFU Cache, Trie, RandomizedSet, Iterator design. Includes 98 problems.
Study Design →Miscellaneous
Recursion, Simulation, Geometry, Concurrency, and JS problems. Includes 112 problems.
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