Hi, here’s your problem today. This problem was recently asked by Uber:
Design a simple 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.
Note: be sure that pop() and top() handle being called on an empty stack.
class minStack(object): def init(self): # Fill this in.
def push(self, x): # Fill this in.
def pop(self): # Fill this in.
def top(self): # Fill this in.
def getMin(self): # Fill this in.
x = minStack() x.push(-2) x.push(0) x.push(-3) print(x.getMin())
-3
x.pop() print(x.top())
0
print(x.getMin())