Chapter 1: Excercises

This page contains a set of excercises for the corresponding chapter.
Read the task description, copy the code template if present and solve it in your Eclipse.
If you are stuck, you can show the solution for this task. Be careful not to spoil the solution for yourself unnecessarily.

Contents

1. Swap Variable Values
2. Speeder
3. User Interaction
4. Circle Area
5. House

Swap Variable Values

Your task is to implement an algorithm which swaps the value of two variables.
Do not just change the values in the code.
You can implement this algorithm by using a temporary variable.
Also, you can do it without a third variable using arithmetic operators.

If initially a is 42 and b is 5, after the execution a should be 5 and b should be 42

program swapVariables import IO main variable a : integer variable b : integer a := 42 b := 5 IO.writeString("Value of a is: ") IO.writeInteger(a) IO.writeString(", value of b is: ") IO.writeInteger(b) IO.writeLine() // IMPLEMENT YOUR SOLUTION HERE // END OF IMPLEMENTATION IO.writeString("Value of a is: ") IO.writeInteger(a) IO.writeString(", value of b is: ") IO.writeInteger(b) IO.writeLine() endmain

Show solution

program swapVariables import IO main variable a : integer variable b : integer a := 42 b := 5 IO.writeString("Value of a is: ") IO.writeInteger(a) IO.writeString(", value of b is: ") IO.writeInteger(b) IO.writeLine() // SOLUTION USING A TEMP VARIABLE variable c : integer c := a a := b b := c // ALTERNATIVE SOLUTION WITHOUT THE VARIABLE // a := a + b // b := a - b // a := a - b IO.writeString("Value of a is: ") IO.writeInteger(a) IO.writeString(", value of b is: ") IO.writeInteger(b) IO.writeLine() endmain

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Speeder

This is a physics textbook excercise.

At the place of a traffic accident, the police determines that the braking distance of a car is 19.0 meters.
The coefficient of friction of the tire material on the road surface is μ = 0,75.

What was the speed of the driver?

The required formula:


program speeder import IO import Strings import Mathematics /* * Our formula: 1/2*(m*v^2) = mu*m*g*s * We need v (km/h), 1m/s = 3,6km/h. * Square root of x = x exp 0.5 */ main variable s : rational variable mu : rational variable g : rational s := 19.0 mu := 0.75 g := 9.81 variable v : rational //IMPLEMENT YOUR SOLUTION HERE // END OF IMPLEMENTATION endmain

Show solution

program speeder import IO import Strings import Mathematics main variable s : rational variable mu : rational variable g : rational s := 19.0 mu := 0.75 g := 9.81 variable v : rational v := (2 * s * g * mu) exp 0.5 // m/s v := v * 3.6 // km/h IO.writeString("The speed of the driver was " & Strings.integerToString(Mathematics.round(v)) & "km/h.\n") endmain

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User Interaction

Your task is to implement a simple user interaction.
The machine should first ask the user what is his or her name.
Then, the machine should greet the user and ask the users age.
Finally, the machine should compute the birth year of the user.
Just use the current year as a number, you cannot query the current date from your machine using MuLE.

The entire interaction could look like this:

Hello, what is your name? Nikita Nice to meet you Nikita, how old are you? 32 So you were born in 1990

program userInteraction import IO main IO.writeString("Hello, what is your name? ") variable name : string name := IO.readString() IO.writeString("Nice to meet you " & name & ", how old are you? ") // IMPLEMENT YOUR SOLUTION HERE // END OF IMPLEMENTATION endmain

Show solution

program userInteraction import IO import Strings main IO.writeString("Hello, what is your name? ") variable name : string name := IO.readString() IO.writeString("Nice to meet you " & name & ", how old are you? ") variable age : integer age := IO.readInteger() IO.writeString("So you were born in " & Strings.integerToString(2022 - age)) endmain

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Circle Area

Your task is to calculate the area of a circle: A = π * r²

Start by declaring the necessary variables: radius, pi and area.

Set radius to 2 and pi top 3.14 and compute and print the area value.
Using these values, the result should be 12.56.

program circleArea import IO import Strings main // TODO: declare variables radius, pi and area // TODO: set initial values for radius (2) and pi (3.14) // TODO: compute the area and print the result endmain

Show solution

program circleArea import IO import Strings import Mathematics main variable radius : integer variable pi : rational variable area : rational radius := 2 pi := 3.14 area := radius exp 2 * pi IO.writeString("The area of the circle is " & Strings.rationalToString(area)) endmain

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House

This is basically a kids game.
Your task is to draw a house using the Turtle library in one go, i.e. without jumping to other locations while drawing.


The variable l_a represents the length of the horizontal and vertical lines.
l_b is the length of the diagonal lines in the house, you have to compute it, for example by using Pythagoras.
l_c is the length of the diagonal lines on the roof, you also have to compute it.

program house import IO import Turtle import Mathematics main Turtle.setPosition(200, 200) Turtle.setDirection(90) variable l_a : integer variable l_b : integer variable l_c : integer l_a := 100 // IMPLEMENT YOUR SOLUTION HERE // END OF SOLUTION endmain

Show solution

program house import IO import Turtle import Mathematics main Turtle.setPosition(200, 200) Turtle.setDirection(90) variable l_a : integer variable l_b : integer variable l_c : integer l_a := 100 l_b := Mathematics.round(((l_a exp 2) * 2) exp 0.5) l_c := Mathematics.round(l_b / 2) Turtle.left(45) Turtle.forward(l_b) Turtle.right(135) Turtle.forward(l_a) Turtle.right(135) Turtle.forward(l_b) Turtle.right(135) Turtle.forward(l_a) Turtle.left(135) Turtle.forward(l_c) Turtle.left(90) Turtle.forward(l_c) Turtle.left(45) Turtle.forward(l_a) Turtle.left(90) Turtle.forward(l_a) endmain

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