Solution to LeetCode 232 Implement Queue using Stacks.
LeetCode 232
Implement Queue using Stacks (Easy) [link]
Python list pop() is an inbuilt function in Python that removes and returns the last value from the List or the given index value.
class MyQueue:
def __init__(self):
self.stack_in = []
self.stack_out = []
def push(self, x: int) -> None:
self.stack_in.append(x)
def pop(self) -> int:
if self.empty:
return None
if self.stack_out:
return self.stack_out.pop()
else:
# for i in range(len(self.stack_in)):
while self.stack_in:
self.stack_out.append(self.stack_in.pop())
return self.stack_out.pop()
def peek(self) -> int:
ele = self.pop()
self.stack_out.append(ele)
return ele
def empty(self) -> bool:
return not (self.stack_in or self.stack_out)
# Your MyQueue object will be instantiated and called as such:
# obj = MyQueue()
# obj.push(x)
# param_2 = obj.pop()
# param_3 = obj.peek()
# param_4 = obj.empty()
