# DIY: Min Stack

Solve the interview question "Min Stack" in this lesson.

## We'll cover the following

## Problem statement

You have to implement the `MinStack`

class, which has a `min()`

function. Whenever `min()`

is called, the minimum value of the stack is returned in *O(1)* time. The element is not popped from the stack. Its value is simply returned.

### Input

The input will be a stream of numbers from which you have to create a min stack.

### Output

The output will return the minimum number in O(1) time.

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