About LinkedList.

Author: Your Name

AlgorithmAndDataStructure/Basic/binary_search.py

@@ -0,0 +1,19 @@
+def binary_search(list, item):
+	low = 0
+	high = len(list) - 1
+
+	while low <= high:
+		mid  = (low+high) // 2
+		guess = list[mid]
+		if guess == item:
+			return print('Yeah,found it:%d'%mid)
+		if guess > item:
+			high = mid - 1
+		else:
+			low = mid + 1
+
+	return print('Oops,there is no one.')
+'''for example'''
+my_list = [1,4,8,9,22,55,65,89,321,2345]
+
+binary_search(my_list, 2345)

AlgorithmAndDataStructure/Basic/linked_list.py

@@ -0,0 +1,350 @@
+#单向链表
+#节点的实现
+class SingleNode(object):
+
+	def __init__(self, item):
+		self.item = item
+		self.next = None
+
+#单链表的实现
+class SingleLinkedList(object):
+
+	def __init__(self):
+		self._head = None
+
+	def is_empty(self):
+		return self._head == None
+
+	def length(self):
+		cur = self._head
+		count = 0
+
+		while cur != None:
+			count += 1
+			cur = cur.next
+
+		return count
+
+	def travel(self):
+		cur = self._head
+
+		while cur != None:
+			print cur.item
+			cur = cur.next
+
+	def add(self, item):
+		#创建一个保存item值的节点
+		node = SingleNode(item)
+		#将新节点的链接域指向头节点
+		node.next = self._head
+		"""_head相当于q变量，让_head变量指向新节点"""
+		self._head = node
+
+	def append(self, item):
+		node = SingleNode(item)
+
+		if self.is_empty():
+			self._head = node 
+
+		else:
+			cur = self._head
+
+			while cur.next != None:
+				cur = cur.next
+
+			cur.next = node 
+"""从头遍历到要插入的位置，将新节点的链接域
+指向插入位置的下一个节点，将。。。找到位置，然后
+打断这条链，强行把新节点插入（把位置的前一个节点
+的链接域指向新节点，新节点的链接域指向下一个节点的
+元素域)"""
+	def insert(self, pos, item):
+		if pos <= 0:
+			self.add(item)
+		elif pos > (self.length() - 1):
+			self.append(item)
+		else:
+			node = SingleNode(item)
+			count = 0
+			pre = self._head
+
+			while count < (pos-1):
+				count += 1
+				pre = pre.next
+
+			node.next = pre.next
+			pre.next = node
+
+	def remove(self, item):
+		cur = self._head
+		pre = None
+
+		while cur != None:
+			if cur.item == item:
+				"""如果头节点为目标节点，则将头指针
+				指向头节点的下一个节点"""
+				if not pre:
+					"""_head是头指针，cur和pre是两个
+					节点"""
+					self._head = cur.next
+				else:
+					pre.next = cur.next
+				break
+			else:
+				pre = cur
+				cur = cur.next
+
+	def search(self, item):
+		if self.is_empty():
+			return
+		 cur = self._head
+		 while cur != None:
+		 	if cur.item == item:
+		 		"""print cur.item
+		 		break"""
+		 		return True
+		 	cur = cur.next
+		 return False
+
+
+"""单向循环链表"""
+class Node(object):
+	def __init__(self, item):
+		self.item = item
+		self.next = None
+
+
+class SinCycLinkedList(object):
+
+	def __init__(self):
+		self._head = None
+
+	def is_empty(self):
+		return self._head == None
+
+	def length(self):
+		if is_empty():
+			return 0
+		cur = self._head
+		count = 0
+		if cur.next == self._head:
+			return 1
+		else:
+			while cur != self._head:
+				count += 1
+				cur = cur.next
+			return count
+
+	def length(self):
+		if is_empty():
+			return 0
+		cur = self._head
+		count = 1
+
+		while cur.next != self._head:
+			count += 1
+			cur = cur.next
+		return count
+
+	def travel(self):
+		if self.is_empty():
+			return
+		cur = self._head
+		print cur.item
+		while cur.next != self._head:
+			cur = cur.next
+			print cur.item
+
+	def add(self, item):
+		node = SingleNode(item)
+		
+		if self.is_empty():
+			self._head = node
+			node.next = self._head
+		else:
+			node.next = self._head
+			cur = self._head
+			while cur.next != self._head:
+				cur = cur.next
+			cur.next = node
+			self._head = node
+
+	def append(self, item):
+		node = Node(item)
+		if self.is_empty():
+			self._head = node
+			node.next = self._head
+		else:
+			cur = self._head
+			while cur.next != self._head:
+				cur = cur.next
+			cur.next = node
+			node.next = self._head
+
+	def insert(self, pos, item):
+		if pos <= 0:
+			self.add(item)
+		elif pos > (self.length() - 1):
+			self.append(item)
+		else:
+			node = Node(item)
+			cur = self._head
+			count = 0
+			while count < (pos-1):
+				count += 1
+				cur = cur.next
+			node.next = cur.next
+			cur.next = node
+
+	def remove(self, item):
+		if self.is_empty():
+			return
+		cur = self._head
+		pre = None
+		if cur.item == item:
+			if cur.next != self._head:
+				while cur.next != self._head:
+					cur = cur.next
+				cur.next = self._head.next
+				self._head = self._head.next
+			else:
+				self._head = None
+		else:
+			pre = self._head
+			while cur.next != self._head:
+				if cur.item ==item:
+					pre.next = cur.next
+					return
+				else:
+					pre = cur
+					cur = cur.next
+			if cur.item == item:
+				pre.next = cur.next
+
+	def search(self, item):
+		if self.is_empty():
+			return False
+		cur = self._head
+		if cur.item == item:
+			return True
+		while cur.next != self._head:
+			cur = cur.next
+			if cur.item == item:
+				return True
+		return False
+
+"""双向链表"""
+class Node(object):
+	def __init__(self, item):
+		self._head = item
+		self.next = None
+		self,prev = None
+
+
+class DLinkList(object):
+	def __init__(self):
+		self._head = None
+
+	def is_empty(self):
+		return self._head == None
+
+	def length(self):
+		cur = self._head
+		count = 0
+		while cur != None:
+			count += 1
+			cur = cur.next
+		return count
+
+	def travel(self):
+		cur = self._head
+		while cur != None:
+			print cur.item
+			cur = cur.next
+
+	def add(self, item):
+		node = Node(item)
+		if self.is_empty():
+			self._head = node
+		else:
+			node.next = self._head
+			self._head.prev = node
+			self._head = node
+
+	def append(self, item):
+		node = Node(item)
+		if self.is_empty():
+			self._head = node
+		else:
+			cur = self._head
+			while cur.next != None:
+				cur = cur.next
+			cur.next = node
+			node.prev = cur
+
+	def search(self, item):
+		cur = self._head
+		while cur != None:
+			if cur.item == item:
+				return True
+			cur = cur.next
+		return False
+
+	def insert(self, pos, item):
+		if pos <= 0:
+			self.add(item)
+		elif pos > (self.length(item)-1):
+			self.append(item)
+		else:
+			node = Node(item)
+			cur = self._head
+			count = 0
+			while count < (pos-1):
+				count += 1
+				cur = cur.next
+			node.prev = cur
+			node.next = cur.next
+			cur.next.prev = node
+			cur.next = node
+
+	def remove(self, item):
+		if self.is_empty():
+			return
+		else:
+			cur = self._head
+			if cur.item == item:
+				if cur.next == None:
+					self._head None
+				else:
+					cur.next.prev = None
+					self._head = cur.next
+				return
+			while cur != None:
+				if cur.item == item:
+					cur.prev.next = cur.next
+					cur.next.prev = cur.prev
+					break
+				cur = cur.next
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