UNIT I - Algorithmic Problem Solving.pptx

Python - ALgorithm Solving

1. UNIT I – Computational thinking and Problem Solving

2. Syllabus Introduction to fundamentals of computing, Algorithms , building blocks of algorithms (statements, state, control flow, functions), notation (pseudo code, flow chart, programming language), algorithmic problem solving, simple strategies for developing algorithms (iteration, recursion). Illustrative problems: find minimum in a list, insert a card in a list of sorted cards, guess an integer number in a range, Towers of Hanoi.

3. Representation of program

4. Algorithm Step by Step description Anybody can easily understand Theoretical explanation of program

5. Building Blocks of Algorithm Incoming Information Step Numbers Control Flow Statements Outgoing Information Step 1 : Start Step 2 : Declare the variables a, b, c Step 3 : Read the values of a and b Step 4 : Calculate c = a+b Step 5 : Display the Output c Step 6 : Stop

6. Building Blocks of Algorithm Incoming Information Step Numbers Control Flow Statements Outgoing Information Step 1 : Start Step 2 : Declare the variables a, b, c Step 3 : Read the values of a and b Step 4 : Calculate c = a+b Step 5 : Display the Output c Step 6 : Stop

7. Building Blocks of Algorithm Incoming Information Step Numbers Control Flow Statements Outgoing Information Step 1 : Start Step 2 : Declare the variables a, b, c Step 3 : Read the values of a and b Step 4 : Calculate c = a+b Step 5 : Display the Output c Step 6 : Stop

8. Building Blocks of Algorithm Incoming Information Step Numbers Control Flow Statements Outgoing Information Step 1 : Start Step 2 : Declare the variables a, b, c Step 3 : Read the values of a and b Step 4 : Calculate c = a+b Step 5 : Display the Output c Step 6 : Stop

9. Building Blocks of Algorithm Incoming Information Step Numbers Control Flow Statements Outgoing Information Step 1 : Start Step 2 : Declare the variables a, b, c Step 3 : Read the values of a and b Step 4 : Calculate c = a+b Step 5 : Display the Output c Step 6 : Stop

10. Building Blocks of Algorithm Incoming Information Step Numbers Control Flow Statements Outgoing Information Step 1 : Start Step 2 : Declare the variables a, b, c Step 3 : Read the values of a and b Step 4 : Calculate c = a+b Step 5 : Display the Output c Step 6 : Stop

11. Ex. Product of two numbers Step 1 : Start Step 2 : Declare the variables a, b, c Step 3 : Read the values of a and b Step 4 : Calculate c = a * b Step 5 : Display the Output c Step 6 : Stop SEQUENCE

12. Ex. 2 odd or even Step 1 : Start Step 2 : Declare the variables n Step 3 : Read the values of n Step 4 : Check if(n%2 ==0), else goto step 5 Step 4.1 : Display that the number is Even number Step 4.2 : Goto step 6 Step 5 : Display that the number is Odd number Step 6 : Stop SELECTION

13. Ex.3 Display the natural numbers upto ‘n’ Step 1 : Start Step 2 : Declare the variables i , n Step 3 : Read the value of n Step 4 : Initialize i =1 Step 5 : Repeat the steps until i <=n, else goto step 6 Step 5.1 : Display ‘ i ’ value Step 5.2 : i =i+1 and goto step 5 Step 6 : Stop ITERATION

14. Ex.3 Display the odd numbers upto ‘n’ Step 1 : Start Step 2 : Declare the variables i , n Step 3 : Read the value of n Step 4 : Initialize i =1 Step 5 : Repeat the step until i <=n, else goto step 6 Step 5.1 : check if (i%2==1), else i =i+1 and goto step 5 Step 5.1.1 : Display ‘ i ’ value, i =i+1 and goto step 5 Step 6 : Stop

15. Flow chart Graphical or symbolic representation Effective understanding documentation Terminator Input / Output Process Decision Flow lines Connectors

16. Ex.1 Product of two numbers Start Read a,b c = a * b Display c Stop

17. Odd or Even Start Read n Display Odd Number Stop Display Even Number If (n%2==0) Yes No

18. Displaying Natural Numbers upto ‘n’ Start Read n Stop Display i If ( i <=n) Yes No i =1 i =i+1

19. Displaying odd Numbers upto ‘n’ Start Read n Stop Display i If ( i <=n) Yes No i =1 i =i+1 If (i%2==1) Yes No

20. Pseudocode Outline of Program High level description of program Uses the keywords Input : READ, OBTAIN, GET, PROMPT Output: PRINT, DISPLAY, SHOW Compute: COMPUTE, CALCULATE, DETERMINE Initiate: SET, INITIALIZE Add one: INCREMENT Keyword should be capitalized Short code of algorithm

21. Ex. Product of two numbers START DECLARE a,b,c READ a,b CALCULATE c=a*b DISPLAY c STOP

22. Ex. Odd or Even START DECLARE n READ n IF n%2 ==0 DISPLAY Even ELSE DISPLAY Odd STOP

23. Ex.3 Display the natural numbers upto ‘n’ START DECLARE i,n INITIALIZE i =1 DO DISPLAY ‘ i ’ i =i+1 UNTIL i <=n END

24. Ex.3 Display the odd numbers upto ‘n’ START DECLARE i,n READ n INITIALIZE i =1 IF(i%2==1) DISPLAY i i =i+1 ELSE i =i+1 UNTIL i <=n END

25. Sum of digits

26. Algorithm Step 1 : Start Step 2 : Declare the variables r , n, c=0 Step 3 : Read the value of n Step 4 : Repeat the steps until n>0, else goto step 5 Step 4.1 : r = n % 10 Step 4.2 : c = c + r Step 4 .3 : n = n / 10 and goto step 4 Step 5 : Display the value of c Step 6 : Stop

27. Flowchart Start Read n Stop If (n>0) Yes No Declare r,n,c =0 c = c+r n = n/10 r = n%10 Display c

28. Pseudocode START DECLARE r , n, c=0 READ n DO r = n % 10 c = c + r n = n / 10 UNTIL n>0 DISPLAY c STOP

29. Fibonacci series

30. Algorithm Step 1 : Start Step 2 : Declare the variables i , a= -1, b=1, c, n Step 3 : Read the value of n Step 4 : Initialize i =1 Step 5 : Repeat the steps until i <=n, else goto step 6 Step 5.1 : c = a + b Step 5.2 : Display c Step 5.3 : a=b Step 5.4 : b=c Step 5.5 : i = i+1 Step 6 : Stop

31. Flowchart Start Read n Stop If ( i <=n) Yes No Declare r,n,c =0 Display c a=b c = a+b i = 1 b=c i = i+1

32. Pseudocode START DECLARE i , a= -1, b=1, c, n READ n Initialize i =1 Do c = a+b Display c a = b b = c i = i+1 UNTIL i <=n STOP