midStacks
Implement two Stacks in one Array.
Updated Apr 28, 2026
Short answer
Start one stack from the left end and the other from the right end.
Deep explanation
Intermediate stack problems often involve monotonic properties or expression conversion. Start one stack from the left end and the other from the right end.
Real-world example
Compiler syntax checking for code blocks.
Common mistakes
- Using a single variable for min-tracking instead of a stack (fails when min is popped).
Follow-up questions
- Time complexity of sorting a stack?