linked list

Add Two Numbers

Add Two Numbers requires careful linked-list pointer manipulation to sum digits while handling carries efficiently in in…

Remove Nth Node From End of List

Remove the nth node from the end of a linked list using a two-pointer approach to solve efficiently.

Merge Two Sorted Lists

Merge two sorted linked lists by splicing nodes into one sorted list using linked-list pointer manipulation and recursio…

Merge k Sorted Lists

Merge k Sorted Lists requires efficiently combining multiple sorted linked lists into one using pointers and priority qu…

Swap Nodes in Pairs

Learn how to swap every adjacent linked-list pair by rewiring nodes safely without changing values or breaking the remai…

Reverse Nodes in k-Group

Reverse Nodes in k-Group challenges you to reverse segments of a linked list in groups of size k.

Rotate List

Rotate a singly linked list to the right by k positions using careful pointer manipulation and two-pointer traversal tec…

Remove Duplicates from Sorted List II

Remove duplicates from a sorted linked list, leaving only distinct values, and return the modified list in sorted order.

Remove Duplicates from Sorted List

Efficiently remove duplicates from a sorted linked list using precise pointer manipulation while maintaining node order …

Partition List

Partition a linked list such that all nodes less than x come before nodes greater than or equal to x while preserving re…

Reverse Linked List II

Reverse a segment of a singly linked list from position left to right using precise pointer manipulation techniques.

Convert Sorted List to Binary Search Tree

Convert a sorted singly linked list into a height-balanced BST using pointer manipulation and divide-and-conquer recursi…

Flatten Binary Tree to Linked List

Flatten a binary tree into a right-skewed linked list by manipulating pointers following a pre-order traversal, handling…

Populating Next Right Pointers in Each Node

Connect each node across every level by reusing established next links to traverse a perfect binary tree without extra q…

Populating Next Right Pointers in Each Node II

Populate each next pointer in a binary tree to its immediate right node, handling nulls and uneven levels efficiently us…

Copy List with Random Pointer

This problem requires copying a linked list where each node has a random pointer in addition to the next pointer.

Linked List Cycle

Determine if a given linked list contains a cycle using pointer manipulation or hashing, focusing on detecting repeated …

Linked List Cycle II

Identify the start of a cycle in a linked list using pointer manipulation, efficiently handling edge cases without modif…

Reorder List

Reorder List requires careful pointer manipulation in a singly linked list to interleave nodes from the ends without alt…

LRU Cache

Implement an efficient LRU Cache using hash table and doubly-linked list to achieve O(1) operations for get and put.

Insertion Sort List

Sort a singly linked list using insertion sort by carefully manipulating pointers to maintain a sorted order efficiently…

Sort List

Sort List requires sorting a singly linked list efficiently using pointer manipulation and merge sort for optimal perfor…

Intersection of Two Linked Lists

Given two linked lists, find the node where they intersect or return null if they do not.

Remove Linked List Elements

Remove all nodes from a linked list that have a specific value, adjusting pointers to preserve the rest of the list.

Reverse Linked List

Reverse a singly linked list in place, converting the head to tail, with an iterative or recursive approach.

Palindrome Linked List

Solve Palindrome Linked List by finding the midpoint, reversing the second half, and comparing mirrored nodes in linear …

Delete Node in a Linked List

Delete Node in a Linked List focuses on pointer manipulation to delete a node in a singly linked list without access to …

Odd Even Linked List

Reorder a singly linked list by grouping odd-indexed nodes first, followed by even-indexed nodes while preserving relati…

Design Twitter

Design Twitter requires implementing post, follow, unfollow, and news feed retrieval using linked-list pointer manipulat…

Linked List Random Node

Select a random node from a singly linked list ensuring uniform probability using efficient pointer techniques and reser…

Flatten a Multilevel Doubly Linked List

Flatten a multilevel doubly linked list by correctly updating next, prev, and child pointers to create a single-level se…

All O`one Data Structure

Implement a data structure that tracks string counts and retrieves max or min keys efficiently in constant time.

Add Two Numbers II

Add Two Numbers II involves summing two numbers represented as linked lists and returning the result as a new linked lis…

LFU Cache

Implement an LFU Cache using linked-list pointer manipulation with constant-time get and put operations for interview sc…

Design Circular Queue

Design a circular queue that allows efficient FIFO operations using linked-list pointer manipulation to optimize space u…

Design Circular Deque

Design and implement a circular deque using linked-list pointer manipulation, ensuring efficient insertion and deletion …

Design HashSet

Implement a custom HashSet without built-in libraries using array scanning and hash lookup for efficient membership chec…

Design HashMap

Implement a custom HashMap from scratch using array scanning and hash lookup without built-in libraries for efficient ke…

Design Linked List

Implement a custom linked list supporting head, tail, index insertions, retrieval, and deletions efficiently with pointe…

Split Linked List in Parts

Efficiently split a singly linked list into k consecutive parts, balancing sizes while preserving the original node orde…

Linked List Components

Count the number of connected components in a linked list subset using array scanning and hash table lookups efficiently…

Middle of the Linked List

Find the middle node of a singly linked list using a two-pointer technique.

Next Greater Node In Linked List

Find the next greater value for each node in a linked list using monotonic stack techniques for efficient traversal.

Remove Zero Sum Consecutive Nodes from Linked List

Remove zero-sum consecutive nodes from a linked list by iterating through it, repeatedly deleting sequences that sum to …

Design Skiplist

Implement a Skiplist efficiently using linked-list pointer manipulation to support search, add, and erase operations in …

Convert Binary Number in a Linked List to Integer

Convert a binary number represented in a linked list to its decimal value using efficient pointer manipulation.

Linked List in Binary Tree

Determine if a linked list is represented as a downward path in a binary tree using pointer traversal and recursive chec…

Design Browser History

Implement a browser history tracker with back, forward, and visit operations using linked-list pointer manipulation effi…

Merge In Between Linked Lists

Merge a second linked list into a first by removing a specified range of nodes, testing precise pointer updates and list…

Design Front Middle Back Queue

Implement a queue that efficiently handles push and pop operations at the front, middle, and back using pointer manipula…

Swapping Nodes in a Linked List

Swap nodes in a linked list using linked-list pointer manipulation and two pointers to solve this medium difficulty prob…

Design Authentication Manager

Implement an AuthenticationManager using linked-list pointer manipulation and a hash map to track token expirations effi…

Find the Minimum and Maximum Number of Nodes Between Critical Points

Find the minimum and maximum number of nodes between critical points in a linked list by identifying local minima and ma…

Reverse Nodes in Even Length Groups

Reverse nodes in even length groups while keeping the odd-length groups intact in a given linked list.

Delete the Middle Node of a Linked List

Efficiently remove the middle node from a linked list using two-pointer techniques and careful pointer updates to mainta…

Maximum Twin Sum of a Linked List

Find the maximum twin sum in a linked list by manipulating pointers efficiently and leveraging stack or reversal techniq…

Merge Nodes in Between Zeros

This problem requires merging nodes between zeros in a linked list by summing up the values between consecutive zeros.

Steps to Make Array Non-decreasing

Determine the minimum steps to make an array non-decreasing using linked-list pointer manipulation and monotonic stack t…

Design a Text Editor

Design a text editor that supports text manipulation and cursor navigation operations efficiently with linked-list-based…

Spiral Matrix IV

In this problem, you need to generate a matrix filled with values from a linked list in a spiral order.

Remove Nodes From Linked List

This problem requires removing nodes from a linked list when a larger node exists to their right, testing pointer manipu…

Insert Greatest Common Divisors in Linked List

The problem involves inserting greatest common divisors between adjacent nodes in a linked list.

Double a Number Represented as a Linked List

Double a number represented as a linked list by carefully managing node values and carries with pointer traversal techni…

Delete Nodes From Linked List Present in Array

Remove nodes from a linked list if their values exist in a given array.

Minimum Pair Removal to Sort Array I

This problem asks for the minimum number of operations to make an array non-decreasing by removing pairs of elements.

Minimum Pair Removal to Sort Array II

The problem asks to find the minimum number of operations to make an array non-decreasing by removing pairs of elements.