Python程式刪除雙向連結串列末尾的新節點
當需要從雙向連結串列的末尾刪除一個節點時,需要建立一個“節點”類。在這個類中,有三個屬性,節點中存在的資料、對連結串列中下一個節點的訪問以及對連結串列中前一個節點的訪問。
下面是相同的演示 -
示例
class Node: def __init__(self, my_data): self.prev = None self.data = my_data self.next = None class double_list: def __init__(self): self.head = None self.tail = None def add_data(self, my_data): new_node = Node(my_data) if(self.head == None): self.head = self.tail = new_node; self.head.previous = None; self.tail.next = None; else: self.tail.next = new_node; new_node.previous = self.tail; self.tail = new_node; self.tail.next = None; def print_it(self): curr = self.head if (self.head == None): print("The list is empty") return print("The nodes in the doubly linked list are :") while curr != None: print(curr.data) curr = curr.next def delete_from_end(self): if(self.head == None): return; else: if(self.head != self.tail): self.tail = self.tail.previous self.tail.next = None; else: self.head = self.tail = None; my_instance = double_list() print("Elements are being added to the doubly linked list") my_instance.add_data(10) my_instance.add_data(24) my_instance.add_data(54) my_instance.add_data(77) my_instance.add_data(92) my_instance.print_it() while(my_instance.head != None): my_instance.delete_from_end(); print("The list after deleting the element from the end is : "); my_instance.print_it();
輸出
Elements are being added to the doubly linked list The nodes in the doubly linked list are : 10 24 54 77 92 The list after deleting the element from the end is : The nodes in the doubly linked list are : 10 24 54 77 The list after deleting the element from the end is : The nodes in the doubly linked list are : 10 24 54 The list after deleting the element from the end is : The nodes in the doubly linked list are : 10 24 The list after deleting the element from the end is : The nodes in the doubly linked list are : 10 The list after deleting the element from the end is : The list is empty
解釋
- 建立“節點”類。
- 建立另一個具有所需屬性的類。
- 定義了一個名為“add_data”的方法,用於將資料新增到雙向連結串列。
- 定義了另一個名為“print_it”的方法,用於顯示迴圈連結串列的節點。
- 定義了另一個名為“delete_from_end”的方法,該方法從末尾刪除節點,即“尾”節點,並將前一個節點設為迴圈連結串列中的尾節點。
- 建立“double_list”類的物件,並在其上呼叫方法以從雙向連結串列的開頭刪除節點。
- 定義了一個“init”方法,將雙向連結串列的根、頭和尾節點設定為None。
- 遍歷列表,並從連結串列的末尾刪除每個節點,直到它為空。
- 使用“print_it”方法在控制檯上顯示此內容。
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