**GATE Important Topics for CSE Students-**

In this article, all the topics of the following subjects which are extremely important from the GATE examination point of view for computer science students have been brought out.

- C, Data Structure and Algorithms
- Theory of Automata and Computation
- Compiler Design
- Digital Logic
- Database Management System
- Computer Organization and Architecture
- Operating System
- Computer Networks

Based on the analysis of previous years GATE exam papers, important topics from these subjects are-

**C, Data Structure and Algorithms-**

- These are the most important subjects from the GATE examination point of view.
- About 25% of the complete paper is from these subjects.
- If you are good in these subjects, it will surely provide a boost to your preparation and will increase your chances of cracking the exam.

**C Programming-**

- C programming questions are mostly based on finding the output of programs consisting of some pointers, static variables, arrays, strings, functions etc.
- So, you must practice solving different kinds of questions.
- It is highly recommended to start practicing now if you are not good at programming.

**Data Structure-**

Practice problems related to-

- Tree like finding number of leaf nodes, number of non leaf nodes, total number of nodes, height of the tree etc
- Binary trees
- Binary Search trees
- Preorder, Inorder and Postorder Traversal
- Spanning trees and minimum spanning tree
- AVL trees and balancing them after insertion and deletion
- Properties of Heap
- Deletion and Insertion of items in heap
- Different problems on stack, queue and linked list (Understand their concepts very well)

**Algorithms-**

Practice problems related to-

- Finding time complexity of given code (Very-very Important)
- Properties of Complexity and relation between them
- Searching and Sorting
- Dynamic Programming Approach
- Divide and Conquer Approach
- Greedy Approach
- Basic problems like knapsack problem, matrix chain multiplication, Longest Common Sub sequence, Job Sequence and Compressing mechanism
- Basic Theory of P-NP problems

**Theory of Automata and Computation-**

Practice questions related to-

- Finding minimum number of states in DFA
- NFA to DFA Conversion
- Closure properties of Finite Automata
- Finding regular expressions
- Mealy Moore Machine
- Simplification of Context Free Grammar
- Pushdown Automata
- Closure Properties of Pushdown Automata
- Finding category of any language or grammar
- Concepts related to expressive power of different languages
- Basic Problems related to NP Completeness
- Properties of Recursive and Recursive Enumerable Languages
- Turing Machine making and expressive power of different types of Turing Machine

Finite Automata covers approximately 50% questions from Theory of Automata and Computation. So, give it more time than others.

**Compiler Design-**

Practice questions related to-

- Parsing and all its techniques (You will always find at least one question from this topic LL(1), LR(1), SLR, LALR, CLR)
- Finding First and Follow
- Precedence and Associativity of operators
- Finding value from expression tree
- Ambiguous Grammar

**Digital Logic-**

Practice questions related to-

- K-Maps (Very high chances of very simple question)
- Multiplexers
- Demultiplexers
- Encoder
- Decoder
- Flip Flops
- Finding modulus of counters
- Floating point representation
- Integer representation
- IEEE Format, Range and Precision

Digital logic contains very simple questions. If you practice them, you can solve all the questions very easily. So, don’t lose your marks here.

**Database Management System (DBMS)-**

Practice questions related to-

- Normalization (No GATE paper is completed without Normalization)
- Finding normal form (comes 70% times in GATE paper)
- Finding candidate keys
- Decomposition of Relation (Lossless Join and Dependency preservation have more chances to appear)
- SQL Queries (Select clause with properties of having, group by, any, all, exits)
- Relational Algebra
- Joins (High probability of tricky questions from Joins)
- Finding view serializability and conflict serializability
- Finding Recoverable and Cascade Schedule
- Lock based, Two phase, Time Stamp and Graph based protocol with their properties like deadlock freedom and starvation freedom
- Formation and structure of B and B+ Trees
- Primary and Clustering Index
- Number of blocks required in indexing of different type
- Collision Resolution
- Minimum and Maximum number of nodes in B and B+ Trees

**Computer Organization and Architecture-**

Practice questions related to-

- Addressing Modes (Theory as well as Numerical Problems)
- Program counter after some instruction
- Number of one address and two address instructions
- Values after shift and rotate instructions
- Horizontal and vertical programming
- Pipelining (Speed up of pipeline, Time taken to complete instruction in pipeline and non-pipeline architectures, Hazards in pipeline, Hazards removal, Branch penalty etc)
- Cache memory organization
- Mapping Techniques
- Multilevel caches
- Write through and write back technique

Questions are more tricky in this subject. So, you need to practice more on different types of questions.

**Operating System-**

Practice questions related to-

- Finding turn around time and waiting time of different scheduling policies. There are more chances for numerical questions to appear from this topic.
- Banker’s Algorithm to check whether given sequence is safe or not.
- Synchronization (Very high chances for questions from this topic)
- Semaphores and classical problems of synchronization (this will help you to solve other questions)
- Memory Management (page table size, number of pages, logical address, physical address, page size, inverted page table, virtual memory, TLB etc.)

**Computer Networks-**

Practice questions related to-

- Addressing (Subnet Address, Supernet Address, Broadcast Address, Range of Network, No. of hosts, Classless Addressing, Non continuous Addresses, Finding first host and last host)
- Flow Control and Error Control Policies (Window Size, Number of Sequence bits, Frame size, Bandwidth, Round trip time, Utilization)
- Properties of Circuit Switching and Packet Switching
- Routing Protocols
- Hamming distance and CRC
- Congestion control policies like slow start, congestion avoidance, congestion detection
- IP Header
- TCP and UDP Header Format
- Theory related to Ethernet and token ring
- Basics of different types of protocols like FTP, HTTP, DHCP, ARP, RARP, SMTP, ICMP, POP
- Basic concepts of cryptography and firewalls

**Best of luck for your preparation!**