py004 - python 單向循環連結清單 代碼

Code:

class Node(object):
    """結點"""
    def __init__(self, elem):
        self.elem = elem
        self.next = None

class SingleCycleLinklist(object):
    """單連結清單"""

    def __init__(self, node = None):
        self.__head = node
        if node != None:
            node.next = node

    def is_empty(self):
        """判斷單連結清單是否為空"""
        return self.__head is None

    def length(self):
        """單連結清單長度"""
        if self.is_empty():
            return 0
        cur = self.__head  # 設定遊标cur
        count = 1  # 設定計數器
        while cur.next != self.__head:
            count += 1
            cur = cur.next
        return count

    def travel(self):
        """周遊單連結清單"""
        if self.is_empty():
            print("空表")
            return
        cur = self.__head  # 設定遊标cur
        while cur.next != self.__head:
            print(cur.elem, end=" ")
            cur = cur.next
        print(cur.elem)
        print("連結清單斷沒有？",'No!' if cur.next is self.__head else 'yes!')

    def add(self, elem):
        """在表頭增加一個元素"""
        if self.is_empty():
            self.__head = node
            node.next = node
        node = Node(elem)
        cur = self.__head
        while cur.next != self.__head:
            cur = cur.next
        cur.next = node 
        node.next = self.__head
        self.__head = node

    def append(self, elem):
        """在表尾增加元素"""
        node = Node(elem)
        if self.is_empty():
            self.__head = node
            node.next = node
        else:
            cur = self.__head  # 設定遊标
            while cur.next != self.__head:
                cur = cur.next
            cur.next = node
            node.next = self.__head
    def insert(self, pos, elem):
        """在指定處增加元素
        :param pos 從0開始 
        """
        if pos <= 0:
            self.add(elem)
        elif pos >= (self.length()-1):
            self.append(elem)
        else:
            node = Node(elem)
            i = 0
            cur = self.__head
            while i < (pos-1):
                cur = cur.next
                i += 1
            node.next = cur.next
            cur.next = node

    def remove(self, elem):
        """删除某一進制素"""
        if self.is_empty():
            print("SingleLinklist is none!")
            return False
        cur = self.__head
        pre = None
        mark = False
        while cur.next != self.__head:
            if cur.elem != elem:
                pre = cur
                cur = cur.next
            else:
                mark = True
                if cur == self.__head:
                    # 頭節點要特殊處理
                    self.__head = self.__head.next    
                    cur = self.__head
                else: 
                    pre.next = cur.next 
                    cur = cur.next
        if cur.elem == elem:
            pre.next = cur.next
        print(mark)  # 顯示是否删除成功

    def search(self, elem):
        """查找某一進制素"""
        if self.is_empty():
            return False
        cur = self.__head
        count = 0
        while cur.next != self.__head:
            if cur.elem == elem:
                return count 
            cur = cur.next
            count += 1
        if cur.elem == elem:
            return count
        return False

if __name__ == "__main__":
    li = SingleCycleLinklist()
    print("添加與周遊測試:")
    print(li.is_empty())
    li.remove(666)
    li.append(1)
    print(li.is_empty())
    li.append(2)
    li.append(3)
    li.append(4)
    li.append(5)
    li.append(6)
    li.travel()
    print(li.length())
    print()
    li.add(0)
    li.append(8)
    li.travel()
    li.insert(3, 666)
    li.travel()
    li.insert(13, 666)
    li.insert(-3, 1000)
    li.travel()
    print("-" * 10)
    print("查找測試:")
    print(li.search(1000))
    print(li.search(7))
    print(li.search(8))
    print("-" * 10)
    print("删除測試")
    li.insert(3, 666)
    li.insert(3, 666)
    li.insert(3, 666)
    li.travel()
    li.remove(666)
    li.remove(666)
    li.travel()
    li.remove(6)
    li.travel()
    li.remove(1000)
    li.remove(8)
    li.travel()
    li.append(6)
    li.travel()
    li.append(6)
    li.travel()
           

OUTPUT