Your Web News in One Place

Help Webnuz

Referal links:

Sign up for GreenGeeks web hosting
June 26, 2021 09:04 pm GMT

LinkedList Questions: Delete a given node in constant time

In this series of posts, I will discuss coding questions on the LinkedList Data structure.
The posts in this series will be organized in the following way,

  1. Question Link
  2. Possible Explanation
  3. Documented C++ Code
  4. Time and Space Complexity Analysis

The Question

Write a function to delete a node in a singly-linked list. You will not be given access to the head of the list, instead you will be given access to the node to be deleted directly.

It is guaranteed that the node to be deleted is not a tail node in the list.

https://leetcode.com/problems/delete-node-in-a-linked-list/

Give yourself atleast 5 mins to figure out the solution :)

Explanation

image

It is a warm-up question, there's not much to explain,

  1. Copy the data of the next node into the given node.
  2. Make the given node point to the next's neighbor.
  3. Free up the old neighbor of the given node.

C++ Code

Definition of LinkedList

//Definition for singly-linked list.struct ListNode{    int val;    ListNode *next;    ListNode() : val(0), next(nullptr) {}    ListNode(int x) : val(x), next(nullptr) {}    ListNode(int x, ListNode *next) : val(x), next(next) {}};

Solution

#include <bits/stdc++.h>#include "../linkedlist.h"using namespace std;/*-Time:O(1)-Space:O(1)*/class Solution{public:    //! given node isn't the "tail" node    void deleteNode(ListNode *node)    {        ListNode *temp = node->next;        //I can do this only because node isn't the tail node        //and "node->next" will not null therefore        node->val = node->next->val;        node->next = node->next->next;        delete temp;    }};

Complexity Analysis

Time Complexity: O(1)

No iteration or recursion is done.

Space Complexity: O(1)

No extra space is used.


Original Link: https://dev.to/kathanvakharia/linked-lists-questions-delete-a-given-node-in-constant-time-1gfp

Share this article:    Share on Facebook
View Full Article

Dev To

An online community for sharing and discovering great ideas, having debates, and making friends

More About this Source Visit Dev To