Lesson 1 - Introduction to Algorithms.pptx
- 1. Introduction to Algorithms Algorithm Analysis & Design March 2020 1 S. Hassan Adelyar, Ph.D Instructor of Computer Science Faculty Kabul University December 2020 Lesson I: Algorithm Analysis & Design
- 2. Introduction to Algorithms Algorithm Analysis & Design March 2020 2 Course Information Course Name: Algorithm Analysis & Design Course Code: SE0601 Credit hours: 4 Reference: Jeffrey J. McConnell (2001). Analysis of Algorithms: An Active Learning Approach. Jones and Bartlett Publishers, Canada. Pre-requisites: Programming Fundamentals, Data Structures and Discreet Mathematics. The contents of the course is divided into 16 lessons. Each lesson include presentation, video, quiz, & discussion. p
- 3. Introduction to Algorithms Algorithm Analysis & Design March 2020 3 Learning Outcome By the end of this presentation, students will be able to: Understand Algorithms Understand the design of Algorithms Understand flow chart & Pseudocode Understand the properties of Algorithms Understand the importance of Algorithms Recognize the types of Algorithms p
- 4. Introduction to Algorithms Algorithm Analysis & Design March 2020 4 Algorithm Series of Steps for solving a problem Set of instructions Transfer input to output Solve a specific task p
- 5. Introduction to Algorithms Algorithm Analysis & Design March 2020 5 Implementing Algorithms p
- 6. Introduction to Algorithms Algorithm Analysis & Design March 2020 6 Example Sorting Searching Find Minimum Find Maximum Find shortest path between two points Etc. p
- 7. Introduction to Algorithms Algorithm Analysis & Design March 2020 7 Algorithms can be expressed in many ways: Flow charts Pseudo-code p
- 8. Introduction to Algorithms Algorithm Analysis & Design March 2020 8 Flow Chart Example p
- 9. Introduction to Algorithms Algorithm Analysis & Design March 2020 9 Pseudo-code p x = 0 while (x < 25) print x end
- 10. Introduction to Algorithms Algorithm Analysis & Design March 2020 10 Properties of Algorithm Finiteness Definiteness Input Output Effectiveness p
- 11. Introduction to Algorithms Algorithm Analysis & Design March 2020 11 Importance of Algorithm Algorithm as a Technology Processing of a large amount of data. Execution time is very important when processing a large amount of input. Algorithms solve the same problem in different time. Differences can be much more than hardware. p
- 12. Introduction to Algorithms Algorithm Analysis & Design March 2020 12 Efficiency: Suppose computers were infinitely fast. Would you have any reason to study algorithm? Good software engineering practice. Select the easiest implementation. New application demand increase in speed. Time is a non-linear function of the input size. This can reduce their ability to benefit from the increase in speed when the input size is large. p
- 13. Introduction to Algorithms Algorithm Analysis & Design March 2020 13 Examples Linear Search & Binary Search Insertion Sort, Merge Sort & Quick Sort Fibonacci by recursion, iteration, dynamic approach p
- 14. Introduction to Algorithms Algorithm Analysis & Design March 2020 14 The execution time of many complex algorithms can vary due to factors other than the size of the input. For example, sorting items that are already sorted. p
- 15. Introduction to Algorithms Algorithm Analysis & Design March 2020 15 Factors that Affect Speed Problem being solved Programming language Compiler Computer hardware Programmer ability Algorithm p
- 16. Introduction to Algorithms Algorithm Analysis & Design March 2020 16 Types of algorithms Recursive Algorithms Backtracking Algorithms Divide-and-conquer Algorithms Dynamic Programming Algorithms Greedy Algorithms Brute Force Algorithms p
- 17. Introduction to Algorithms Algorithm Analysis & Design March 2020 17 Summary In this presentation, we studied Algorithms & Algorithm design techniques. The presentation of Algorithm with the flowchart & pseudocode was explained with examples. In addition to Algorithm, the properties of Algorithms, importance of Algorithms & types of Algorithms were explained p
- 18. Introduction to Algorithms Algorithm Analysis & Design March 2020 18 Exercises Write an algorithm in pseudo-code to count the number of capital letters in a file of text. How many comparisons does it do? What is the fewest number of increments it might do? What is the largest number? There is a set of numbers stored in a file, but we don’t know how many it contains. Write an algorithm in pseudo-code to calculate the average of the numbers stored in this file. What type of operations does your algorithm do? How many of each of these operations does your algorithm do? p
- 19. Introduction to Algorithms Algorithm Analysis & Design March 2020 19 Write an algorithm to find the second largest element in a list of N values. How many comparisons does your algorithm do in the worst case? 1- Write an algorithm and draw a flowchart to convert the length in feet to centimeter. 2- Write an algorithm and draw a flowchart that will read the two sides of a rectangle and calculate its area. p
- 20. End of Lesson 1 Question?