Implement a Min-Stack (getting min in O(1)).

Updated Apr 28, 2026

Short answer

Using an auxiliary stack to track the minimum element at each level.

Deep explanation

Intermediate stack problems often involve monotonic properties or expression conversion. Using an auxiliary stack to track the minimum element at each level.

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?

Short answer

Deep explanation

Real-world example

Common mistakes

Follow-up questions

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