GDSC DSA WorkShop GDSC Pillai College of Engineering

DSA workshop gdsc pce

1. DSA Workshop (Day 1)

2. About me DSA/CP Lead @GDSC PCE In top 7.93% of all users on leetcode Max Rating (1355) on Codeforces Solved over 1500+ DSA/CP problems Smart India Hackathon 2019 Finalist Full Stack Developer (MERN) Stack YASH DABHADE TY COMPS

3. 01 Brush up basics Contents of the workshop 02 Intro to DSA 03 Time and Space Complexity

4. 04 Arrays Contents of the workshop 05 Stacks 06 Queues

5. 07 HashMap Contents of the workshop 08 LinkedList 09 Searching

6. Brush up basics 01

7. Intro to Programming A programming language is a set of instructions written by a programmer to tell a computer how to perform a task Some popular languages

8. Data Types Data types are used to inform a programming language's compiler or interpreter about the data that will be used. Data Types are classified as : Pre Defined User Defined

9. Variables Variables are containers for storing data values. Syntax : data_type variable_name; Scopes of Variables : Local Variable Global Variable

10. Scope of variable

11. Operators Arithmetic Operators

12. Operators Assignment Operators

13. Operators Relational Operators

14. Operators Logical Operators

15. Operators Bitwise Operators

16. Conditional Statements Conditional statements in C++ are control structures that let code make decisions Syntax : if (condition) { code… } else{ Code.. }

17. Example of if-else

18. I terative Statements The looping can be defined as repeating the same process multiple times until a specific condition satisfies. Types of loops :

19. While loop

20. Do-while loop

21. For loop

22. Functions A function is a block of code that performs a specific task. Functions are classified as : Standard Library Functions User-defined Function

23. User-defined Function

24. Pointers A pointer however, is a variable that stores the memory address as its value. Syntax : data_type *pointer_name = address; Applications of pointers: Operating System Various Data Structures

25. Introduction to DSA 02

26. Introduction to DSA Data Structures and Algorithms (DSA) is a fundamental part of Computer Science that teaches you how to think and solve complex problems systematically. Benefits of Learning DSA : Improve problem solving skills Able to perform better in Online Assessment Easily able to code complex logics Breaking a problem into small pieces and making working solutions for them

27. Myth DSA is boring and not used in real life

28. Language to choose Speed : Fastest Fast Slow Available 90% 8% 2% Solutions: Library STL Collection Inbuilt Modules Used :

29. Platforms Available Pure DSA Competitive Programming

30. Time Complexity What is Time Complexity ? Types of Time Complexity Why it is important ?

31. TC Cheatsheet

32. How to calculate TC x=y+10-z O(1) Time Complexity x=2*y+z O(1) Time Complexity if(x>y and z*2>y){ O(1) Time Complexity cout<<x<<endl; }

33. How to calculate TC for(int i=0;i<n;i++) { O(n) Time Complexity cout<<i<<endl; } for(int i=0;i<n;i++{ O(n^2) Time Complexity for(int j=0;j<n;j++){ cout<<i<<” “<<j<<endl; } }

34. How to calculate TC for(int i=0;i<n;i++{ O(n^3) Time Complexity for(int j=0;j<n;j++){ for(int j=0;j<n;j++){ cout<<i<<” “<<j<<” “<<k<<endl; } } } int n=1000; O(log2(n)) Time Complexity while(n>2) { n/=2; }

35. Space Complexity What is Space Complexity ? Why it is important ?

36. Space Complexity Int arr[n]; for(int i=0;i<n;i++) { O(n) Space Complexity cout<<arr[i]<<endl; } Int arr[n][n]; for(int i=0;i<n;i++{ O(n^2) Space Complexity for(int j=0;j<n;j++){ cout<<arr[i][j]<<endl; } }

37. Classification 01 Linear (Arrays, Stacks, Queues, LinkedList) Data Structures 02 Non Linear (HashMap, Graphs, Trees)

38. Arrays/Vectors What is Arrays ? How vectors are different ? Functions in Vectors : push_back(element) pop_back() back() erase() clear() Vector in C++ 0 1 2 3 4

39. Vector Functions

40. Let’s solve problems https://leetcode.com/problems/buy-two-chocolates/ https://leetcode.com/problems/move-zeroes/description/

41. Stacks What is Stack? LIFO Data Structure Functions : push(element) pop() top() size() empty() clear()

42. Stack Functions

43. Let’s solve problems https://leetcode.com/problems/valid-parentheses/ https://leetcode.com/problems/removing-stars-from-a-string/description/?envType=study-plan-v2&envId=leetcode-75

44. Queue What is Queue? F IFO Data Structure Functions : push(element) pop() front() back() empty() size()

45. Queue Functions

46. Circular Queue Double Ended Queue

47. Priority Queue What is Priority Queue? Min-Heap/Max-Heap Functions : push(element) pop() top() empty() size()

48. HashMap What is HashMap ? Constraints on HashMap

49. Pair What is pair? Can we pair elements of different data type ?

50. Problems https://leetcode.com/problems/sort-characters-by-frequency/

51. Linked List What is Linked List ? Why Linked List is not preferred ? Functions : Not inbuilt data structure

52. Types of Linked List Doubly Linked List

53. Problems https://leetcode.com/problems/reverse-linked-list/ Try this on your own : https://leetcode.com/problems/add-two-numbers/description/

54. Searching (Linear) Why is searching required ? Types of search : Linear Search Binary Search

55. Problems (Linear) https://leetcode.com/problems/binary-search/description/ https://leetcode.com/problems/minimum-common-value/?envType=daily-question&envId=2024-03-11

56. Miscellaneous Problems https://leetcode.com/problems/custom-sort-string/?envType=daily-question&envId=2024-03-11 https://leetcode.com/problems/missing-number/description/?envType=daily-question&envId=2024-03-11

57. Thanks! Feel free to ask any questions? https://twitter.com/YashD283 https://www.linkedin.com/in/yashdabhade283/