Queue and Deque coding problems

Queues and deques power level-order processing, sliding window maximums and simulation problems. Practise using the right end at the right time.

16 problems: 9 easy, 7 medium, 0 hard. Free to read; a free account solves them and earns XP and Aura.

1. Duplicate Element RemoverPractice · +10 XP · queue, simulation, seteasy
2. Find the First Negative NumberPractice · +10 XP · queue, simulation, arrayseasy
3. First Unique CharacterPractice · +10 XP · queue, string, frequency mapeasy
4. Print Elements with Even IndexPractice · +10 XP · queue, simulation, basic iterationeasy
5. Print Queue ContentsPractice · +10 XP · queue, simulation, basic programmingeasy
6. Process First In First OutPractice · +10 XP · queue, simulation, beginnereasy
7. Queue ReverserPractice · +10 XP · queue, stack, simulationeasy
8. Reverse First K ElementsPractice · +10 XP · queue, stack, simulationeasy
9. Sequence ReverserPractice · +10 XP · queue, deque, simulationeasy
10. Balanced Parentheses SubsequencePractice · +20 XP · queue, stack, simulationmedium
11. Find Minimums in Sliding WindowsPractice · +20 XP · heaps, sliding window, dequemedium
12. Largest Element in PrefixPractice · +20 XP · queue, monotonic deque, simulationmedium
13. Longest Prefix With Maximum FrequencyPractice · +20 XP · queue, simulation, monotonic dequemedium
14. Maximum Subarray Sum with Fixed LengthPractice · +20 XP · queue, sliding window, prefix summedium
15. Next Greater Element in a Cyclic ArrayPractice · +20 XP · queue, stack, monotonic stackmedium
16. Sliding Window MinimumPractice · +20 XP · queue, sliding window, monotonic dequemedium