Learn Coding Interview
Master the patterns behind coding interview problems, from hash maps to dynamic programming.
About this track
Coding interviews ask you to solve algorithm problems while explaining your thinking. This track teaches a repeatable problem-solving routine, Big O analysis, and the patterns that unlock most interview questions: hash maps, two pointers, sliding windows, binary search, stacks, linked lists, heaps, trees, graphs, dynamic programming, and backtracking. Every lesson ends with a classic interview problem you solve in Python, right in your browser.
- Comfort writing basic Python: loops, functions, lists, and dictionaries.
- No prior algorithms course needed.
- The first exercise run loads the Python runtime in your browser.
- Unit 1 · 0/2 lessons
Approach and complexity
A problem-solving routine and Big O analysis. Badge: Problem solver
- 0x001Solve problems out loudUse a repeatable routine from clarifying questions to tested code. 20 min 0/1 exercises solved 20 min 0/1 exercises solved
- 0x102Analyze time and space complexityDescribe how running time and memory grow with input size. 20 min 0/1 exercises solved 20 min 0/1 exercises solved
- Unit 2 · 0/4 lessons
Arrays and strings
Hash maps, two pointers, sliding windows, and binary search. Badge: Pattern spotter
- 0x203Trade memory for speed with hash mapsUse dictionaries and sets to replace nested loops with lookups. 20 min 0/1 exercises solved 20 min 0/1 exercises solved
- 0x304Walk inward with two pointersUse two indices to solve sorted-array and palindrome problems in O(n). 20 min 0/1 exercises solved 20 min 0/1 exercises solved
- 0x405Track a range with a sliding windowGrow and shrink a window to solve substring and subarray problems in O(n). 20 min 0/1 exercises solved 20 min 0/1 exercises solved
- 0x506Halve the search space with binary searchSearch sorted data - or any monotonic condition - in O(log n). 20 min 0/1 exercises solved 20 min 0/1 exercises solved
- Unit 3 · 0/3 lessons
Stacks, lists, and heaps
Stacks, queues, linked lists, and priority queues. Badge: Structure builder
- 0x607Match and order with stacks and queuesUse LIFO and FIFO structures for nesting, undo, and level-by-level work. 20 min 0/1 exercises solved 20 min 0/1 exercises solved
- 0x708Rewire linked listsReverse, merge, and detect cycles by moving node pointers carefully. 20 min 0/1 exercises solved 20 min 0/1 exercises solved
- 0x809Find the top k with heapsUse a priority queue to get the smallest or largest items quickly. 20 min 0/1 exercises solved 20 min 0/1 exercises solved
- Unit 4 · 0/2 lessons
Trees and graphs
Recursive tree traversal, BFS, and DFS. Badge: Graph explorer
- 0x9010Traverse trees recursivelySolve binary tree problems by combining answers from subtrees. 20 min 0/1 exercises solved 20 min 0/1 exercises solved
- 0xA011Explore graphs with BFS and DFSModel problems as graphs and search them without revisiting nodes. 20 min 0/1 exercises solved 20 min 0/1 exercises solved
- Unit 5 · 0/2 lessons
Advanced techniques
Dynamic programming and backtracking. Badge: Algorithm architect
- 0xB012Reuse answers with dynamic programmingBreak problems into overlapping subproblems and solve each once. 20 min 0/1 exercises solved 20 min 0/1 exercises solved
- 0xC013Generate choices with backtrackingBuild candidates step by step and undo choices to explore every option. 20 min 0/1 exercises solved 20 min 0/1 exercises solved