Write a Program in C++ that calculates the amount of paint needed to paint the walls of a room?

Question

A room has one door, two windows, and a built-in bookshelf and it needs to be painted. Suppose that one gallon of paint can paint 120 square feet.

Write a program that prompts the user to input (in feet):

1. The length and width of the door
2. The length and width of each window
3. The length and width of the bookshelf
4. The length, width, and height of the room
5. The area that can be painted with one gallon of paint

The program outputs:

1. The amount of paint needed to paint the walls of the room.

Answer 1

Here's the code:

#include <iostream>

using namespace std;

int main() {

// Variables for our input

int doorLength;

int doorWidth;

int windowLength;

int windowWidth;

int roomLength;

int roomWidth;

int roomHeight;

int areaPerGallon;

// Ask for values

cout << "What is the length of the door in feet? ";

cin >> doorLength;

cout << "What is the width of the door in feet? ";

cin >> doorWidth;

cout << "What is the length of the window in feet? ";

cin >> windowLength;

cout << "What is the width of the window in feet? ";

cin >> windowWidth;

cout << "What is the length of the room in feet? ";

cin >> roomLength;

cout << "What is the width of the room in feet? ";

cin >> roomWidth;

cout << "What is the height of the room in feet? ";

cin >> roomHeight;

cout << "What is the area that can be painted with on gallon of paint? ";

cin >> areaPerGallon;

// The paintable area is the four walls minus one door and two windows

int paintableArea = 2 * roomWidth * roomHeight + 2 * roomLength * roomHeight - doorLength * doorWidth - 2 * windowLength * windowWidth;

// Calculate gallons needed

double gallonsNeeded = (double)paintableArea / areaPerGallon;

cout << "You need " << gallonsNeeded << " gallons of paint." << endl;

return 0;

}

And it's output:

> ./main

What is the length of the door in feet? 7

What is the width of the door in feet? 3

What is the length of the window in feet? 4

What is the width of the window in feet? 5

What is the length of the room in feet? 10

What is the width of the room in feet? 15

What is the height of the room in feet? 9

What is the area that can be painted with on gallon of paint? 120

You need 3.24167 gallons of paint.