Fundamental Programming Lect 4
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This document recaps previous lectures on programming fundamentals and decision making in computer programs. It discusses defining problems, designing solutions using flowcharts, and incorporating decision boxes to allow for conditional logic. Decision rules always involve comparisons and can check for multiple conditions using logical operators like AND and OR. Examples demonstrate how to divide a number conditionally based on the second number's value, and how to determine a student's status based on marks in multiple subjects. The next lecture will include an on-the-spot test to assess understanding of these concepts.
Fundamental Programming Lect 4
- 1. Instructor : Muhammad HarisAll Rights Reserved to Department of Computer Science – GCU Lahore Programming Fundamentals
- 2. Recap of Previous Lectures To solve a problem using computers, we need to do the following: 1. Define the problem (in terms of inputs, outputs and processing) 2. Design a solution for it (using a graphical approach) ○ Symbols used Oval – Start and Stop Parallelogram – Input and Output Rectangle - Processing Diamond - Decision box Programming Fundamentals | Lecture-4 2
- 3. Recap of Previous Lectures Problems we looked at Sum, Product, Difference of two numbers Square or cube of a number Solving an equation or a formula involving 3, 4 variables ○ Example Some formulae from elementary physics or an algebraic equation Programming Fundamentals | Lecture-4 3
- 4. Recap of Previous Lectures Decision making is required in many real-world problems Computer programs can be very useful in this regard To incorporate decision making in our solutions we learnt the usage of “Decision box” Programming Fundamentals | Lecture-4 4 Decision Rule YesNo Always in the form whose answer is “Yes” or “No”
- 5. Recap of Previous Lectures We always make comparisons in a decision box or Decision Rules are always in the form of comparisons Examples ○ difference < 0 ○ sum > 0 ○ number2 != 0 ○ marks >= 50 Programming Fundamentals | Lecture-4 5
- 6. Recap of Previous Lectures To determine the usage of decision rule, follow these steps 1. Define inputs and outputs 2. Is decision-making required in this solution? 3. What are the basis of decision? ○ the thing which is required to make a decision will appear in the decision box 1. What kind of comparison is required in the decision box? Programming Fundamentals | Lecture-4 6
- 7. Recap of Previous Lectures Problems we looked at Checking negativity of a number Checking equality of two numbers Multiplying or Dividing two numbers conditionally Checking status of a student Programming Fundamentals | Lecture-4 7
- 8. Tasks (from previous lecture) Find whether the sum of two numbers is greater than 50 Find whether the sum of two numbers is greater than the third number? Divide a number by another if only if the second number is not equal to “0” Determine whether a student is “passed” or “failed” from his marks A student securing marks less than 50 is considered “failed” Programming Fundamentals | Lecture-4 8
- 9. Decision Rules So far 1 decision rule in a decision box Examples ○ difference < 0 ○ number2 != 0 ○ marks < 50 Programming Fundamentals | Lecture-4 9 difference < 0 number2 != 0 marks< 50
- 10. Consider This Example Divide a number by another if the second number is greater than “0” and less than “10” Divide a number by another if the second number is between “0” and “10” (also known as range check) Programming Fundamentals | Lecture-4 10 OR
- 11. Programming Fundamentals | Lecture-4 11 START READ num1, num2 DISPLAY answer STOP answer = num1 / num2 num2 > 0 YesNo
- 12. More than 1 Decision Rule Programming Fundamentals | Lecture-4 12 START READ num1, num2 DISPLAY answer STOP answer = num1 / num2 num2 > 0 AND num2 < 10 YesNo
- 13. Another Example Add two numbers if either of them is “0” Programming Fundamentals | Lecture-4 13
- 14. Another Example Determine status of a Students from marks of two of his subjects If marks for both the subjects are greater than 40 he’s considered passed Programming Fundamentals | Lecture-4 14
- 15. Another Example Determine status of a Students from marks of two of his subjects If marks for any of the subjects is greater than 40 he’s considered passed Programming Fundamentals | Lecture-4 15
- 16. Programming Fundamentals | Lecture-4 16 BE PREPARED FOR ON-THE-SPOT TEST IN NEXT LECTURE