1 SEE IT
Watch the animation until the movement feels obvious. If you can picture it, you can code it.
2 SAY IT
Every pattern has a one-line story — a train window, a tortoise and a hare, two bouncers. Say it out loud once.
3 CODE IT
Steal the template, do the 3 classic problems listed, then tap “Got it” and move on. Recognition beats memorization.
0 of 25 patterns locked inTap a card, watch it move, hit “Got it ✓”
No pattern matches that search. Try “window”, “heap”, or “graph”.
Pattern 01 · Arrays & Strings
Sliding Window
Spot it in the interview when you hear…
The story that makes it stick
Code template · Python
The 3 classics to practice
The 4-week plan that actually fits a job
About 45–60 minutes a day. One pattern per sitting: watch, say the story, code the template from memory, do one classic. Weekends are for redoing the ones that felt shaky — not new ones.
Week 1 · Arrays
The bread & butter
- Sliding Window, Two Pointers
- Fast & Slow, Prefix Sum, HashMap
- Binary Search, Monotonic Stack
- Redo day + 1 mock
Week 2 · Structures
Lists, trees, heaps
- Merge Intervals, Cyclic Sort
- Linked List Reversal, Tree BFS & DFS
- Two Heaps, Top K, K-Way Merge
- Redo day + 1 mock
Week 3 · Graphs & choices
Where offers are won
- Topological Sort, Backtracking
- Greedy, Graph Traversal, Union Find
- Trie, Bit Manipulation, Matrix Islands
- Redo day + 1 mock
Week 4 · DP + mocks
Make it automatic
- DP Patterns + Knapsack DP
- Re-do your 5 weakest patterns
- 3 timed mocks (45 min each)
- Say every story out loud once
All 25 at a glance
Tap any row to load that pattern's animation above. Print this page and stick the table on your wall — interviewers ask from this list far more than you'd expect.
| # | Pattern | One-line trigger | Complexity |
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