LeetCode[day10] - Min Stack

Design a stack that supports push, pop, top, and retrieving the minimum element in constant time. push(x) -- Push element x onto stack. pop() -- Removes the element on top of the stack. top() -- Get the top element. getMin() -- Retrieve the minimum element in the stack. Methods pop, top and getMin operations will always be called on non-empty stacks. Input ["MinStack","push","push","push","getMi..