Introduction to Computing
Lecture 00: Part 3
Introduction to Algorithms and
Flowcharts (continued)
Assist.Prof.Dr. Nükhet ÖZBEK
Ege University
Department of Electrical&Electronics
Engineering
[email protected]
Expressing Algorithms
• Natural Languages
• Pseudocode
• Flowcharts
• Programming Languages
Natural Language Algorithm
Cilbir
• 6 eggs
• ½ kg yogurt
• 3 large garlic cloves
• 4 Tbs fresh butter
• 1 tsp red pepper, coarsely ground
• 2 middle-sized onions cut horizontally
• plenty water
• Boil water in a fairly big pot. Break one by one the eggs and pour them in a
•
•
plate, being careful not to break the yolk. To ensure a homogenous
cooking, let them “glide” from the plate into the boiling water. Within three
minutes the eggs are ready but if you prefer hard-boiled, allow them to
cook for another minute or so.
Meanwhile brown the butter in a skillet and add the garlic and onion. In the
last possible moment add the coarsely ground red pepper and turn off the
fire. Remove the eggs from the pot using a skimmer and place them in a
deep plate.
Cover the eggs with plenty of yogurt and pour the hot butter over them.
Serve immediately.
From www.gourmet.gr
Pseudocode Algorithm Example
Set moveCount to 1
FOR each row on the board
FOR each column on the board
IF gameBoard position (row, column) is occupied THEN
CALL findAdjacentTiles with row, column
INCREMENT moveCount
END IF
END FOR
END FOR
Algorithm Example
Set number counter to zero
Set sum to zero
While (number counter < 10)
{
input a number
Sum = Sum + Number
increment number counter by 1
}
Calculate average = sum / 10
Labwork 1
• Write an algorithm to calculate the area of
circle
Labwork 1
Input radius
Set pi = 3.14
Calculate area = pi * radius * radius
Labwork 2
• Write an algorithm to calculate the sum of
multiples of 3 up to 100
Labwork 2
Set number counter to zero
Set sum to zero
While (number counter < 100)
{
Sum = Sum + Number counter
increment number counter by 3
}
Flowcharts
• Flowcharts are schematic representations of
•
•
processes
Generally the start point, end points, inputs,
outputs, possible paths and the decisions that
lead to these possible paths are included
Flow-charts can be created by hand or manually
in most office software, but lately specialized
diagram drawing software has emerged that can
also be used for the purpose
Flowchart Symbols (Mostly Used)
• Start / End symbol
• Arrows
• Processing steps
• Input/Output
• Conditional (Decision)
Flowchart Symbols (Others)
• Document
• Magnetic Tape
• Display
• Manual Input
Flowchart Example
From wikipedia.org
Flowchart Example
From smartdraw.com
Flowchart Example
Read NAME, BALANCE, RATE
Compute INTEREST as BALANCE x RATE
Write (Display) NAME and INTEREST
Flowchart Example
From wikipedia.org
Flowchart Example
START
Input N
Sum =0
C=0
Input number
Sum = Sum + number
C=C+1
No
C = N?
Yes
A = Sum / N
Print A
END
Labwork 3
• Draw a flowchart to find the sum of first
50 counting numbers
Labwork 3
Labwork 4
• Draw a flowchart to find the largest of
three numbers A,B, and C.
Labwork 5
• Draw a flowchart to find the product of
two numbers using only addition operation
Labwork 5
Labwork 6
• Draw a flowchart to find the division of
two integer numbers using only
subtraction operation. Find the division
and remainder.
Labwork 6
Summary
• Problem Solving Process
• Algorithms
• Components of Algorithms
• Flowcharts