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Data Structures and Algorithms in Python

Remove Node

Explore the process of removing nodes in circular linked lists using Python. Understand the handling of special cases like deleting the head node and traversing the list to remove other nodes. This lesson provides a complete implementation and explanation to help you master node removal operations in circular linked lists.

We'll cover the following...

In this lesson, we investigate how to remove nodes in a circular linked list and code the method in Python.

There is an assumption that we will make before diving into the implementation:

  • The occurrences of nodes will be unique, i.e., there will be no duplicate nodes in the circular linked list that we’ll test on.

This is because the code that we will write will only be responsible for removing the first occurrence of the key provided to be deleted.

Implementation

Now let’s go ahead and jump to the implementation of remove in Python:

Python 3.5
def remove(self, key):
  if self.head:
    if self.head.data == key:
      cur = self.head 
      while cur.next != self.head:
        cur = cur.next 
      if self.head == self.head.next:
        self.head = None
      else:
        cur.next = self.head.next
        self.head = self.head.next
    else:
      cur = self.head 
      prev = None 
      while cur.next != self.head:
        prev = cur 
        cur = cur.next
        if cur.data == key:
          prev.next = cur.next 
          cur = cur.next

Explanation

The code is divided into parts based on whether or not we are deleting the ...