Process a sequence of MinStack operations. push, pop, top, and getMin must all run in constant time.
Return one output per operation. Constructors, push, and pop produce null; top and getMin produce numbers.
Inputoperations = ["MinStack", "push", "push", "push", "getMin", "pop", "top", "getMin"], values = [[], [-2], [0], [-3], [], [], [], []]
Output[null, null, null, null, -3, null, 0, -2]
Inputoperations = ["MinStack", "push", "getMin", "top"], values = [[], [5], [], []]
Output[null, null, 5, 5]
At most 30,000 operations are performed.