Algorithms and Flowcharts: A Guide to Solving Programming Tasks, Assignments of C programming

Download Algorithms and Flowcharts: A Guide to Solving Programming Tasks and more Assignments C programming in PDF only on Docsity!

COVERED BASICS ABOUT ALGORITHMS AND FLOWCHARTS

ALGORITHMS AND FLOWCHARTS



A typical programming task can be divided into

two phases:



Problem solving phase

 (^) produce an ordered sequence of steps that describe solution of problem  (^) this sequence of steps is called an algorithm 

Implementation phase

 (^) implement the program in some programming language

PSEUDOCODE & ALGORITHM

 Example 1: Write an algorithm to determine a student’s final grade and indicate whether it is passing or failing. The final grade is calculated as the average of four marks.

PSEUDOCODE & ALGORITHM

Pseudo code :



Input a set of 4 marks



Calculate their average by summing and

dividing by 4



if average is below 50

Print “FAIL”

else

Print “PASS”

THE FLOWCHART

 (Dictionary) A schematic representation of a sequence of operations, as in a manufacturing process or computer program.  (Technical) A graphical representation of the sequence of operations in an information system or program. Information system flowcharts show how data flows from source documents through the computer to final distribution to users. Program flowcharts show the sequence of instructions in a single program or subroutine. Different symbols are used to draw each type of flowchart.

THE FLOWCHART

A Flowchart  (^) shows logic of an algorithm  (^) emphasizes individual steps and their interconnections  (^) e.g. control flow from one action to the next

EXAMPLE 1

PRINT “PASS ” Step 1: Input M1,M2,M3,M Step 2: Step 3: GRADE (M 1 +M2+M 3 +M4)/ if (GRADE <50) then Print “FAIL” else Print “PASS” endif STAR T Input M1,M2,M3,M GRADE (M1+M2+M3+M4)/ IS GRADE< 0 PRINT “FAIL ” STOP N Y

EXAMPLE 2

 Write an algorithm and draw a flowchart to convert the length in feet to centimeter. Pseudo code :  Input the length in feet (Lft)  (^) Calculate the length in cm (Lcm) by multiplying LFT with 30  Print length in cm (LCM)

EXAMPLE 3

Write an algorithm and draw a flowchart

that will read the two sides of a rectangle

and calculate its area.

Pseudocode



Input the width (W) and Length (L) of a

rectangle



Calculate the area (A) by multiplying L with

W



Print A

Algorithm  Step 1:  Step 2:  Step 3: Input W,L A L x W Print A STAR T Input W, L A L x W Print A STOP

Pseudo code :  Input the coefficients (a, b, c) of the quadratic equation  (^) Calculate d  Calculate x 1  Calculate x  Print x 1 and x



Algorithm :

 (^) Step 1: Input a, b, c  (^) Step 2:  (^) Step 3:  (^) Step 4:  (^) Step 5: Print x 1, x 2 d sqrt ( (^) b b 4 a c ) x 1 (– b + d ) / (2 x a ) x 2 (– b – d ) / (2 x a ) STAR T Input a, b, c d sqrt( b x b – 4 x a x c ) STOP x 1 (– b + d ) / (2 x a ) X 2 (– b – d ) / (2 x a ) Print x 1 , x 2

DECISION STRUCTURES

is A>B Print B Print A Y N

IF–THEN–ELSE STRUCTURE

 The structure is as follows: If condition then true alternative else false alternative endif