designFrontMiddleBackQueue.py

#! /usr/bin/env python3
# -*- coding: utf-8 -*-

# Source: https://leetcode.com/problems/design-front-middle-back-queue/
# Author: Miao Zhang
# Date:   2021-05-26

class FrontMiddleBackQueue:

    def __init__(self):
        self.q = []

    def pushFront(self, val: int) -> None:
        self.q.insert(0, val)

    def pushMiddle(self, val: int) -> None:
        self.q.insert(len(self.q) // 2, val)

    def pushBack(self, val: int) -> None:
        self.q.append(val)

    def popFront(self) -> int:
        if self.q:
            return self.q.pop(0)
        return -1

    def popMiddle(self) -> int:
        if self.q:
            return self.q.pop((len(self.q) - 1) // 2)
        return -1

    def popBack(self) -> int:
        if self.q:
            return self.q.pop(-1)
        return -1


# Your FrontMiddleBackQueue object will be instantiated and called as such:
# obj = FrontMiddleBackQueue()
# obj.pushFront(val)
# obj.pushMiddle(val)
# obj.pushBack(val)
# param_4 = obj.popFront()
# param_5 = obj.popMiddle()
# param_6 = obj.popBack()