Lab Session-XII CSIT121 Spring 2002

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Lab Session-XII CSIT121 Spring 2002

• Arrays and Their Usage
• Finding the largest element
• Lab Exercise 12-A
• Lab Demo (12-B)
• Practice Problems

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Arrays and Their Usage

• Arrays hold similar and related data items
  however data values are different
• We can use arrays in any program where we have to
  deal with large amount of similar data using an
  INDEX into the data

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Finding Largest Value

• Often we will need to find the largest value in
  an array.
• We can designate the first element as the largest
  in the beginning
• As we compare one by one, we change mind if a
  larger value is found

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Lab Exercise 12-A

• Let us define an array and initialize it with
  some values
• const int PLACES15
• int distancesPLACES24,56,78,24,
• 12,94,18,91,77,11,97,82,45,95,88
• We wish to find the largest distance value in
  this array

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Lab Exercise 12-A

• Data Modeling
• an array int distances
• an integer largest as index to largest value
• Algorithm
• largest0, for (1 to PLACES-1) Repeat 1 2
• 1. Designate distanceslargest as largest
• 2. Compare with current value and change the
  largest index if found higher

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Lab Exercise 12-B (Demo Required)

• Develop a program that keeps information of names
  and ages of a group of 5 people.. An array of
  structs is recommended. This program calls a
  function and passes the array to it. The function
  prints the names and ages of all people in a
  nicely formatted way. Sample Data that can be
  used is as follows

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Sample Data for Ex 12-B

• Jason Anderson, 21
• Christina Smith, 35
• Brian Smith Jr., 42
• Derek Dustin, 18
• Jason Geiger, 19

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Practice Problem

• Given an array of ID numbers of library
  defaulters, search for the occurrence of a
  specific ID number to see if this person is a
  library defaulter or not
• Data Modeling
• int defaultersMAXSIZE
• int target_ID
• bool not_found

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Practice Problem

• Algorithm
• not_foundtrue
• While (not_found)
• Match the target_ID with contents of the
  defaulters array one by one
• If matched, assign not_foundfalse
• Else if array end reached, person not found

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Sample Data

• const int MAXSIZE20
• int defaultersMAXSIZE
• 2435,1211,7643,2437,9834,2001,1029,1290,
• 2340,2200,1214,4438,2105,4355,8254,9120,
• 2502,9403,1006,1205
• target_ID 8254
• target_ID2000

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Additional Practice Problems

• Define a union that can hold temperature. The
  temperature can be stored in degrees Celsius or
  degrees Fahrenheit. Assign 35 degrees Celsius to
  the appropriate union member and display. Then
  convert it to Fahrenheit, store and display
• Modify 12-B to include a union in the struct.
  This union should be able to sore the age in
  months or years

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For Lab 13, Demo Problem

• Write a value returning recursive function that
  implements the recursive formula
• F(N) F(N-1) F(N-2)
• Where F(1) equals 9 and F(0) equals 3
• HINT The base case here could be reached when
  N-1 equals 1 and N-2 equals zero