Check if absolute difference of consecutive nodes is 1 in Linked List in Python

Suppose, we have a singly linked list where each node contains an integer value. We have to find out if the absolute difference between two successive nodes is 1.

So, if the input is like start_node->5->6->7->8->7->6->5->4, then the output will be True.

To solve this, we will follow these steps −

• temp := start_node
• while temp is not null, do
  • if temp.link is same as null, then
    • come out from the loop
  • if |value of (temp) - value of (temp.link)| is not same as 1, then
    • return False
  • temp := temp.link
• return True

Example

Let us see the following implementation to get better understanding −

 Live Demo

import math class link_node:    def __init__(self, value):       self.value = value       self.link = None def create_node(value):    temp = link_node(value)    temp.value = value    temp.link = None    return temp def make_list(elements):    head = link_node(elements[0])    for element in elements[1:]:       ptr = head       while ptr.link:          ptr = ptr.link       ptr.next = link_node(element)    return head def solve(start_node):    temp = start_node    while (temp):       if (temp.link == None):          break       if (abs((temp.value) - (temp.link.value)) != 1) :          return False       temp = temp.link    return True start_node = make_list([5, 6, 7, 8, 7, 6, 5, 4]) print(solve(start_node))

Input

[5, 6, 7, 8, 7, 6, 5, 4]

Output

True