Linked listPractice Question

Duration: 3 min

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Inside: a video lesson and guided study material.

Module outline

  1. Quantitative Aptitude: Number System, Divisibility Rules, HCF LCM, Percentage, Ratio and Proportion (Ratios), Average, Profit and Loss, Simple Interest and Compound Interest, Mixture and Alligation, Partnership, Age Problems, Time and Work, Pipe and Cistern, Speed Time and Distance, Algebra, Arithmetic, Data Interpretation, Sequence and Series (Series), Logarithm, Powers and Exponents (Surds and Indices), Permutation and Combination, Probability, Speed Mathematics and Basic Mathematics, Trigonometry
  2. Logical Reasoning: Coding Decoding, Blood Relations, Directions (Direction Test), Ranking, Order and Sequence, Seating Arrangements, Puzzle Solving (Puzzles), Data Arrangement, Syllogisms, Inequality, Data Sufficiency, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Series (Number and Letter Series) (Numerical Relations and Reasoning), Venn Diagram, Logical Sequence Of Words, Calendar, Clock, Cubes & Dices, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning)
  3. Verbal Ability: Noun, Pronoun, Adjectives, Verb, Adverb, Tenses, Subject Verb Agreement (Verb Noun Agreement), Articles, Preposition, Conjunction, Modals, Determiner, Vocabulary, Comprehension / Reading Comprehension / Unseen Passages (Critical Reasoning) (Paragraph Questions), Cloze Test (Cloze Passage), Sentence Correction (Error Correction), Sentence Completion (Fill in the blanks), Sentence Re-arrangements (Para Jumbles) (Narrative Sequencing), Active Passive Voice (Voice), Direct and Indirect Speech, Sentence Construction
  4. Data Structures (Domain Test): Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing
  5. Algorithms (Domain Test): Algorithm Analysis, Sorting Algorithms, Time Complexity Analysis, Greedy Algorithms
  6. OOPs (Domain Test): Object Oriented Programming (OOPS)
  7. DBMS (Domain Test): Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, File Organization & Indexing, Relational Algebra, Relational Calculus, Transaction Management, Concurrency Control, Database Recovery, ORDBMS, Database Security & Authorization, Query Processing & Optimization, Enhanced Data Models, Data Warehousing & Mining, Big Data Systems, NoSQL
  8. SQL (Domain Test): SQL
  9. Operating Systems (Domain Test): Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Deadlock, Threads & Process Creation, Memory Management, Virtual Memory, Disc Scheduling, File Management, Windows OS, Linux OS, Security, Distributed Systems, Virtual Machines
  10. Computer Networks (Domain Test): Introduction to CN, Data Communication, DLL: Access Control, DLL: Flow Control, DLL: Error Control, DLL: Framing, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Net Layer:Routing Protocol, Transport Layer Services, TL: Congestion & UDP, Application Layer, Hardware basics, Network Security, Mobile Technology, Cloud Computing and IoT, Cyber and Info Security
  11. Coding: Coding Questions by Yash Sir, C Programming by Yash Sir, Programming in C++, Java, Python for Placements by Yash Sir
  12. Written English Test: English Writing Ability
  13. Psychometric Test: Behavioral Assessment (Behavioral Competency Profiling) (Psychometric Test)
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This educational video features Sanchit Jain from KnowledgeGate explaining how to reverse a singly linked list in C. The lecture begins by presenting a function `reverse` that accepts a double pointer `head_ref`. The instructor details the iterative algorithm, initializing `prev` to NULL and `current` to the head. He draws a diagram of nodes A, B, C, and D to illustrate the pointer manipulation. The core logic involves a `while` loop that iterates through the list, reversing the `next` pointer of each node to point to the previous node. The lesson culminates in identifying the missing statement required to update the head of the list after the reversal is complete.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The instructor introduces the problem of reversing a singly linked list. He displays the C code for the `reverse` function, highlighting the initialization of `prev` to NULL and `current` to `*head_ref`. He draws a diagram of a linked list (A->B->C->D) and explains the `while` loop logic: saving the next node, reversing the current node's pointer to point to `prev`, and moving `prev` and `current` forward. He emphasizes that `head_ref` is a double pointer. He draws arrows to show the reversal process, explaining how `current` moves from the head to the tail while `prev` moves from NULL to the new head.

  2. 2:00 – 2:58 02:00-02:58

    The instructor focuses on the missing line at the end of the function. He presents multiple-choice options for the final statement: (A) `*head_ref = prev;`, (B) `*head_ref = current;`, (C) `*head_ref = next;`, and (D) `*head_ref = NULL;`. He explains that after the loop finishes, `prev` points to the new head of the reversed list. Since `head_ref` is a double pointer, it needs to be updated to point to this new head. He concludes that `*head_ref = prev;` is the correct statement to update the head pointer, selecting option (A) and circling it on the screen.

The lecture progresses from explaining the iterative reversal algorithm to identifying the critical final step. The instructor uses visual aids (diagrams) and code analysis to demonstrate how pointers are manipulated. The key takeaway is understanding that reversing the internal pointers of nodes is not enough; the external head pointer must also be updated to point to the new first node, which is the last node processed in the loop (stored in `prev`). This ensures the list is correctly accessible from the new head.

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