## Assignment #2 - Using Selection Statements

Due: Mon, June 7

### Objective

This assignment will consist of writing two small programs, which will give practice with basic selection statements, as well as further practice with basic I/O.

Write the following programs, each in a separate file. Filenames should be:
• sort.cpp
• wave.cpp
(Note that the filenames are all lowercase)

### Exercise 1

Write a program (filename sort.cpp) that does the following:

Prompt the user and let them enter three integers. Store them in three variables. Print the numbers in sorted order, from smallest to largest.

Sample run: (user input underlined)

```  Input integer 1 : 34
Input integer 2 : 200
Input integer 3 : -14

Sorted : -14 <= 34 <= 200
```

### Exercise 2

Filename: wave.cpp

This is based on Programming Challenge 18 in chapter 4 of your textbook. This table shows the approximate speed of sound in air, water, and steel.
MediumSpeed
Air1,100 feet per second
Water4,900 feet per second
Steel16,400 feet per second

Write a program that does the following:

• Display a menu allowing the user to select air, water, or steel. Prompt the user and allow them to enter a choice. User entry should be a character: 'A' for air, 'W' for water, and 'S' for steel. Allow both uppercase and lowercase as valid entries
• If the user enters an invalid choice, print an appropriate error message and end the program.
• For a valid choice, now ask the user to enter the distance that a sound wave will travel through the selected medium. (Use type double for this entry).
• If the selected distance is negative, this is an invalid choice, so print an error message and end the program.
• For a valid distance, compute and display the amount of time it will take for the sound wave to travel the given distance, rounded to 4 decimal places.

### Sample Runs

(user input is underlined, to distinguish it from output)

#### Sample run 1

```Welcome to Sound Wave Calculator

Select the medium the sound wave will travel through.
A       Air
W       Water
S       Steel

> A
How far will the sound wave travel (in feet)? 3500
The sound wave will travel 3.1818 seconds
Goodbye
```

#### Sample run 2

```Welcome to Sound Wave Calculator

Select the medium the sound wave will travel through.
A       Air
W       Water
S       Steel

> w
How far will the sound wave travel (in feet)? 3500
The sound wave will travel 0.7143 seconds
Goodbye
```

#### Sample run 3

```Welcome to Sound Wave Calculator

Select the medium the sound wave will travel through.
A       Air
W       Water
S       Steel

> s
How far will the sound wave travel (in feet)? 98765
The sound wave will travel 6.0223 seconds
Goodbye
```

#### Sample run 4

```Welcome to Sound Wave Calculator

Select the medium the sound wave will travel through.
A       Air
W       Water
S       Steel

> z
Illegal entry. Aborting program.
Goodbye
```

#### Sample run 5

```Welcome to Sound Wave Calculator

Select the medium the sound wave will travel through.
A       Air
W       Water
S       Steel

> S
How far will the sound wave travel (in feet)? -10
Distance cannot be negative.  Aborting program.
Goodbye
```

### Requirements for both programs

• No global variables, other than constants
• All input and output must be done with streams, using the library iostream
• You may only use the iostream library (you do not need any others for these tasks)
• When you write source code, make sure it is clear, readable, and well-documented.

### Submitting:

Submit only your source code files through the web submission page. As there are two of them, this will require filling out the submission page twice. Make sure to click on "Assigment 2" both times. Submit the files:
```  sort.cpp
wave.cpp
```