栈操作
class Stack(object):
def __init__(self):
self.items = []
def is_empty(self):
return 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 size(self):
return len(self.items)
stack = Stack()
stack.push("hello")
stack.push("world")
stack.push("itcast")
print(stack.size())
print(stack.peek())
print(stack.pop())
print(stack.pop())
print(stack.pop())
运行结果：
3
itcast
itcast
world
hello
Process finished with exit code 0
队列
"""
队列操作-housong
Queue() 创建一个空的队列
enqueue(item) 往队列中添加一个item元素
dequeue() 从队列头部删除一个元素
is_empty() 判断一个队列是否为空
size() 返回队列的大小
"""
class Queue(object):
def __init__(self):
self.items = []
def is_empty(self):
return self.items == []
def enqueue(self,item):
# 进队列-从后面
# self.items.append(item)
self.items.insert(0,item)
def dequeue(self):
# 出队列-从前面
# return self.items.pop(0)
return self.items.pop()
def size(self):
return len(self.items)
q = Queue()
q.enqueue("hello")
q.enqueue("world")
q.enqueue("itcast")
print(q.size())
print(q.dequeue())
print(q.dequeue())
print(q.dequeue())
运行结果：
3
hello
world
itcast
Process finished with exit code 0
双端队列
class Deque(object):
"""双端队列"""
def __init__(self):
self.items = []
def is_empty(self):
"""判断队列是否为空"""
return self.items == []
def add_front(self, item):
"""在队头添加元素"""
self.items.insert(0,item)
def add_rear(self, item):
"""在队尾添加元素"""
self.items.append(item)
def remove_front(self):
"""从队头删除元素"""
return self.items.pop(0)
def remove_rear(self):
"""从队尾删除元素"""
return self.items.pop()
def size(self):
"""返回队列大小"""
return len(self.items)
if __name__ == "__main__":
deque = Deque()
deque.add_front(1)
deque.add_front(2)
deque.add_rear(3)
deque.add_rear(4)
print(deque.size())
print(deque.remove_front())
print(deque.remove_front())
print(deque.remove_rear())
print(deque.remove_rear())
运行结果：
4
2
1
4
3
Process finished with exit code 0
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