本文实例讲述了Python编程实现双链表，栈，队列及二叉树的方法。分享给大家供大家参考，具体如下：
1.双链表
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class Node(object): def __init__(self, value=None): self._prev = None self.data = value self._next = None def __str__(self): return "Node(%s)"%self.dataclass DoubleLinkedList(object): def __init__(self): self._head = Node() def insert(self, value): element = Node(value) element._next = self._head self._head._prev = element self._head = element def search(self, value): if not self._head._next: raise ValueError("the linked list is empty") temp = self._head while temp.data != value: temp = temp._next return temp def delete(self, value): element = self.search(value) if not element: raise ValueError('delete error: the value not found') element._prev._next = element._next element._next._prev = element._prev return element.data def __str__(self): values = [] temp = self._head while temp and temp.data: values.append(temp.data) temp = temp._next return "DoubleLinkedList(%s)"%values |
2. 栈
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class Stack(object): def __init__(self): self._top = 0 self._stack = [] def put(self, data): self._stack.insert(self._top, data) self._top += 1 def pop(self): if self.isEmpty(): raise ValueError('stack 为空') self._top -= 1 data = self._stack[self._top] return data def isEmpty(self): if self._top == 0: return True else: return False def __str__(self): return "Stack(%s)"%self._stack |
3.队列
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class Queue(object): def __init__(self, max_size=float('inf')): self._max_size = max_size self._top = 0 self._tail = 0 self._queue = [] def put(self, value): if self.isFull(): raise ValueError("the queue is full") self._queue.insert(self._tail, value) self._tail += 1 def pop(self): if self.isEmpty(): raise ValueError("the queue is empty") data = self._queue.pop(self._top) self._top += 1 return data def isEmpty(self): if self._top == self._tail: return True else: return False def isFull(self): if self._tail == self._max_size: return True else: return False def __str__(self): return "Queue(%s)"%self._queue |
4. 二叉树（定义与遍历）
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class Node: def __init__(self,item): self.item = item self.child1 = None self.child2 = Noneclass Tree: def __init__(self): self.root = None def add(self, item): node = Node(item) if self.root is None: self.root = node else: q = [self.root] while True: pop_node = q.pop(0) if pop_node.child1 is None: pop_node.child1 = node return elif pop_node.child2 is None: pop_node.child2 = node return else: q.append(pop_node.child1) q.append(pop_node.child2) def traverse(self): # 层次遍历 if self.root is None: return None q = [self.root] res = [self.root.item] while q != []: pop_node = q.pop(0) if pop_node.child1 is not None: q.append(pop_node.child1) res.append(pop_node.child1.item) if pop_node.child2 is not None: q.append(pop_node.child2) res.append(pop_node.child2.item) return res def preorder(self,root): # 先序遍历 if root is None: return [] result = [root.item] left_item = self.preorder(root.child1) right_item = self.preorder(root.child2) return result + left_item + right_item def inorder(self,root): # 中序序遍历 if root is None: return [] result = [root.item] left_item = self.inorder(root.child1) right_item = self.inorder(root.child2) return left_item + result + right_item def postorder(self,root): # 后序遍历 if root is None: return [] result = [root.item] left_item = self.postorder(root.child1) right_item = self.postorder(root.child2) return left_item + right_item + resultt = Tree()for i in range(10): t.add(i)print('层序遍历:',t.traverse())print('先序遍历:',t.preorder(t.root))print('中序遍历:',t.inorder(t.root))print('后序遍历:',t.postorder(t.root)) |
输出结果：
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层次遍历: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]先次遍历: [0, 1, 3, 7, 8, 4, 9, 2, 5, 6]中次遍历: [7, 3, 8, 1, 9, 4, 0, 5, 2, 6]后次遍历: [7, 8, 3, 9, 4, 1, 5, 6, 2, 0] |
希望本文所述对大家Python程序设计有所帮助。
原文链接：http://www.cnblogs.com/PrettyTom/p/6677993.html
