Queue data structure, deque, and circular queue problems.
- FIFO (First In First Out) principle
- Queue implementation
- Circular queue
- Deque (double-ended queue)
- Sliding window maximum
- Queue using stacks
- BFS applications
- Use std::queue for basic FIFO operations
- Use std::deque for double-ended operations
- Queue is natural for BFS traversal
- Sliding window problems often use deque
- Consider monotonic deque for optimization