Min Stack
Detailed guide and Python implementation for the 'Min Stack' problem.
Problem Statement
Design a stack that supports push, pop, top, and retrieving the minimum element in constant time.
Implement the MinStack class:
- MinStack() initializes the stack object.
- push(val: int) pushes the element val onto the stack.
- pop() removes the element on the top of the stack.
- top() -> int gets the top element of the stack.
- getMin() -> int retrieves the minimum element in the stack.
You must implement a solution with O(1) time complexity for each function.
- •-2^31 <= val <= 2^31 - 1
- •Methods pop, top, and getMin are always called on non-empty stacks
- •At most 3 * 10^4 calls will be made to push, pop, top, and getMin
Examples
["MinStack", "push", "push", "push", "getMin", "pop", "top", "getMin"] [[], [-2], [0], [-3], [], [], [], []]
[None, None, None, None, -3, None, 0, -2]
MinStack created. Push -2, 0, -3. getMin() returns -3. Pop removes -3. top() returns 0. getMin() returns -2.
Need a Hint?
Edge Cases to Watch
- Empty input structures
- Single element inputs
- Large numerical bounds
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