Solution: Min Stack

Statement

Design a stack data structure to retrieve the minimum value in $O(1)$ time. The following functions must be implemented:

• min(): Returns the minimum value in the stack in constant time.
• push(int value): Pushes a value onto the stack.
• pop(): Removes and returns a value from the top of the stack.

All functions should be implemented with a time complexity of $O(1)$.

Constraints:

• $-10^5 \leq$ value $\leq 10^5$