Python实现栈队列双端队列

Posted 2021-02-20 孙小龙

栈的实现

class Stack():
    def __init__(self):
        self.items = []

    def push(self, item):
        self.items.append(item)

    def pop(self):
        return self.items.pop()

    def peek(self):
        return self.items[len(self.items)-1]

    def isEmpty(self):
        return len(self.items) == 0

    def size(self):
        return len(self.items)

stack=Stack()
stack.push(1)
stack.push(2)
stack.push(3)
print(stack.peek())
print(stack.pop())
print(stack.pop())
print(stack.pop())

队列的实现

#coding:utf8
class Queue():
    def __init__(self):
        self.items = []

    def enqueue(self, item):
        self.items.insert(0, item)

    def dequeue(self):
        return self.items.pop()

    def isEmpty(self):
        return len(self.items) == 0

    def size(self):
        return len(self.items)

# queue = Queue()
# queue.enqueue(1)
# queue.enqueue(2)
# queue.enqueue(3)
# print(queue.size())
# print(queue.dequeue())
# print(queue.dequeue())
# print(queue.dequeue())

队列算法之烫手的山芋

kids = ["A", "B", "C", "D", "E", "F"]  # 参加游戏的孩子
queue = Queue()
for kid in kids:
    queue.enqueue(kid)
while queue.size() > 1:
    for i in range(6):
        queue.enqueue(queue.dequeue())
    queue.dequeue()
print(queue.dequeue())

双端队列的实现

# coding:utf8
# 队列  ：尾部--->首部
class Deque():
    def __init__(self):
        self.items = []

    def addFront(self, item):
        self.items.append(item)

    def addRear(self, item):
        return self.items.insert(0, item)

    def removeFront(self):
        return self.items.pop()

    def removeRear(self):
        return self.items.pop(0)

    def isEmpty(self):
        return len(self.items) == 0

    def size(self):
        return len(self.items)

双端队列算法之回文检测

# 实现回文检查
def isHuiWen(_str):
    flag = True
    deque = Deque()
    for i in _str:
        deque.addFront(i)
    while deque.size() > 1:
        if deque.removeFront() != deque.removeRear():
            flag = False
            break
    return flag


print(isHuiWen("hooh"))
print(isHuiWen("hoioh"))
print(isHuiWen("hoijoh"))