用Python實現單向迴圈連結串列
阿新 • • 發佈:2018-11-11
直接看程式碼,有詳細註解
class Node(object): """節點""" def __init__(self, elem): self.elem = elem self.next = None class SingleCycleLinkList(object): """單向迴圈連結串列""" def __init__(self, node=None): self.__head = node if node: node.next = node def is_empty(self): """連結串列是否為空""" return self.__head == None def length(self): """連結串列長度""" if self.is_empty(): return 0 # cur遊標,用來移動遍歷節點 cur = self.__head # count記錄數量 count = 1 while cur.next != self.__head: count += 1 cur = cur.next return count def travel(self): """遍歷整個連結串列""" if self.is_empty(): return cur = self.__head while cur.next != self.__head: print(cur.elem, end=" ") cur = cur.next # 退出迴圈,cur指向尾節點,但尾節點的元素未列印 print(cur.elem) def add(self, item): """連結串列頭部新增元素,頭插法""" node = Node(item) if self.is_empty(): self.__head = node node.next = node else: cur = self.__head while cur.next != self.__head: cur = cur.next # 退出迴圈,cur指向尾節點 node.next = self.__head self.__head = node # cur.next = node cur.next = self.__head def append(self, item): """連結串列尾部新增元素, 尾插法""" node = Node(item) if self.is_empty(): self.__head = node node.next = node else: cur = self.__head while cur.next != self.__head: cur = cur.next # node.next = cur.next node.next = self.__head cur.next = node def insert(self, pos, item): """指定位置新增元素 :param pos 從0開始 """ if pos <= 0: self.add(item) elif pos > (self.length()-1): self.append(item) else: pre = self.__head count = 0 while count < (pos-1): count += 1 pre = pre.next # 當迴圈退出後,pre指向pos-1位置 node = Node(item) node.next = pre.next pre.next = node def remove(self, item): """刪除節點""" if self.is_empty(): return cur = self.__head pre = None while cur.next != self.__head: if cur.elem == item: # 先判斷此結點是否是頭節點 if cur == self.__head: # 頭節點的情況 # 找尾節點 rear = self.__head while rear.next != self.__head: rear = rear.next self.__head = cur.next rear.next = self.__head else: # 中間節點 pre.next = cur.next return else: pre = cur cur = cur.next # 退出迴圈,cur指向尾節點 if cur.elem == item: if cur == self.__head: # 連結串列只有一個節點 self.__head = None else: # pre.next = cur.next pre.next = self.__head def search(self, item): """查詢節點是否存在""" if self.is_empty(): return False cur = self.__head while cur.next != self.__head: if cur.elem == item: return True else: cur = cur.next # 退出迴圈,cur指向尾節點 if cur.elem == item: return True return False if __name__ == "__main__": ll = SingleCycleLinkList() print(ll.is_empty()) print(ll.length()) ll.append(1) print(ll.is_empty()) print(ll.length()) ll.append(2) ll.add(8) ll.append(3) ll.append(4) ll.append(5) ll.append(6) # 8 1 2 3 4 5 6