Here I've implemented solution for the below "min stack" question using std::vector as a simple console application. All the operations work with a time complexity O(1). It has been successfully tested for operations like push, pop, top, min etc. (the test results are displayed on the console).
[Question] 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.