Iterator LeetCode Problems: All 9, With Python Solutions
Every problem in this library that LeetCode tags Iterator — 9 in total, 5 of them with a complete Python solution, a worked example and the time and space complexity of the approach.
- 9 problems
- 1 Easy
- 8 Medium
- 0 Hard
Iterator problems by difficulty
Problems with a complete Python solution are listed first, then by ascending problem number.
Easy (1)
| # | Problem | Difficulty | Topics |
|---|---|---|---|
| 604 | Design Compressed String IteratorPremium | Easy | Design, Array, String +1 |
Medium (8)
| # | Problem | Difficulty | Topics |
|---|---|---|---|
| 173 | Binary Search Tree Iterator | Medium | Stack, Tree, Design +3 |
| 284 | Peeking Iterator | Medium | Design, Array, Iterator |
| 341 | Flatten Nested List Iterator | Medium | Stack, Tree, Depth-First Search +3 |
| 900 | RLE Iterator | Medium | Design, Array, Counting +1 |
| 1286 | Iterator for Combination | Medium | Design, String, Backtracking +1 |
| 251 | Flatten 2D VectorPremium | Medium | Design, Array, Two Pointers +1 |
| 281 | Zigzag IteratorPremium | Medium | Design, Queue, Array +1 |
| 1586 | Binary Search Tree Iterator IIPremium | Medium | Stack, Tree, Design +3 |
Keep exploring
All LeetCode topicsEvery tag with a page of its own, with the number of problems behind each.LeetCode patternsThe techniques themselves, with a Python template and complexity for each.Curated study listsBlind 75, NeetCode 150 and three more, grouped by pattern.Easy problemsStart here when the data structure is new rather than the problem.
Other topics
- Array1,569
- String672
- Hash Table588
- Math485
- Dynamic Programming481
- Sorting392
- Greedy346
- Depth-First Search289
- Binary Search253
- Database249
- Tree225
- Breadth-First Search223
- Matrix216
- Two Pointers201
- Bit Manipulation194
- Binary Tree174
- Heap (Priority Queue)163
- Prefix Sum157
- Stack157
- Simulation144
- Graph138
- Counting126
- Design122
- Sliding Window116
When the Iterator problem arrives live
Stealth Interview is a desktop app for macOS and Windows. It reads the coding problem off your screen, returns a working solution with a step-by-step explanation and its time and space complexity, and transcribes what the interviewer is saying — while staying invisible to screen sharing.