Python开发中常见的数据结构问题及解决策略

class Node:
    def __init__(self, data):
        self.data = data
        self.next = None

def reverse_list(head):
    prev, current = None, head
    while current:
        next_node = current.next
        current.next = prev
        prev = current
        current = next_node
    return prev

# 创建一个链表
list_head = Node(1)
list_head.next = Node(2)
list_head.next.next = Node(3)
list_head.next.next.next = Node(4)

# 反转链表
reversed_list = reverse_list(list_head)

# 打印反转后的链表
current = reversed_list
while current:
    print(current.data)
    current = current.next

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

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

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

    def pop(self):
        if not self.is_empty():
            return self.items.pop()

    def peek(self):
        if not self.is_empty():
            return self.items[-1]

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

# 创建一个栈，并进行操作
my_stack = Stack()
my_stack.push(1)
my_stack.push(2)
my_stack.push(3)

print(my_stack.peek())  # 输出3
print(my_stack.pop())   # 输出3
print(my_stack.size())  # 输出2

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

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

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

    def dequeue(self):
        if not self.is_empty():
            return self.items.pop(0)

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

# 创建一个队列，并进行操作
my_queue = Queue()
my_queue.enqueue(1)
my_queue.enqueue(2)
my_queue.enqueue(3)

print(my_queue.dequeue())   # 输出1
print(my_queue.size())      # 输出2
print(my_queue.is_empty())  # 输出False

class Node:
    def __init__(self, data):
        self.data = data
        self.left = None
        self.right = None

def preorder_traversal(root):
    if root:
        print(root.data)
        preorder_traversal(root.left)
        preorder_traversal(root.right)

# 创建一个二叉树
root = Node(1)
root.left = Node(2)
root.right = Node(3)
root.left.left = Node(4)
root.left.right = Node(5)

# 对二叉树进行前序遍历
preorder_traversal(root)