Week 05 Tutorial Sample Answers

Arrays Practice

This week, we will discuss arrays, and complete a program to practice writing arrays.

Diagram of an array

Tutor Demo! (10 mins)

We have been provided the following program that intends to do the following steps but has some flaws.

Create an integer array with at least 5 elements.
Create a while loop which loops through every element of the array.
Write an if statement which adds 1 to each even value. Do this within the while loop.
Write another while loop which goes through the array with a different iterator (i.e. if you used i last time, use j)
Print out the values in the array.

Flowchart of activity

// part1_arrays.c, odd_only
//
// Written by YOUR-NAME (YOUR-ZID)
// on TODAYS-DATE 
//
// This program adds 1 to any odd element in an array and after prints 
// all elements in the array

#include <stdio.h>

#define SIZE 5

int main(void) {

    int array = {1, 2, 3, 4, 5};

    int i = 0;
    while (i < SIZE) {
        if (array.i % 2 == 0) {
            array.i += 1;
        }
    }

    int j = 1;
    while (j < SIZE) {
        printf("%c ", array.j);
    }

    printf("\n");

    return 0;
}

We will go through and debug the program so it executes as expected.

Ask students what an array is, briefly outline it's purpose and why we might use one. Draw an integer array on the whiteboard (similar to the one above), and explain what each component is. Show the flowchart describing what the program should do. Debug the program provided so than it performs as expected. While debugging show a few different debugging techniques: - Using printf to see what is happening at different points of the program - Reading dcc output and interpreting it - Utilising dcc-help - Utilising dcc-sidekick Solution below:

// part1_arrays, even_only
//
// Written by Sofia De Bellis, z5418801
// on March 2024
//
// This program adds 1 to any odd values in an array

#include <stdio.h>

#define SIZE 5

int main(void) {

    int array[SIZE] = {1, 2, 3, 4, 5};

    int i = 0;
    while (i < SIZE) {
        if (array[i] % 2 == 1) {
            array[i] += 1;
        }
        i++;
    }

    int j = 0;
    while (j < SIZE) {
        printf("%d ", array[j]);
        j++;
    }

    printf("\n");

    return 0;
}

Your turn!

Copy Array

Create an array of doubles with 3 elements, each with a non-zero value.
Create another array of doubles with 10 elements where every element initialised to 0.0.
Create a while loop that loops through every element of the first array.
Copy the elements of the first array into the second array (leave 0's at the end)
Create a while loop that prints out all the elements of the second array.

Largest Character
Create a character array with exactly 8 elements.
Create a character variable called largest_character, equal to the first character of the array.
Create a while loop to loop through the character array.
Create an if statement to check if the current character has a higher ascii value than "largest_character"
Print out the largest character you've found.

Arrays Practice

Tutor Demo! (10 mins)

Your turn!

Copy Array

Largest Character