Write a function that returns the earned points in a single toss of a Darts game.
Darts is a game where players throw darts to a target.
In our particular instance of the game, the target rewards with 4 different amounts of points, depending on where the dart lands:
The outer circle has a radius of 10 units (This is equivalent to the total radius for the entire target), the middle circle a radius of 5 units, and the inner circle a radius of 1. Of course, they are all centered to the same point (That is, the circles are concentric) defined by the coordinates (0, 0).
Write a function that given a point in the target (defined by its real
cartesian coordinates x
and y
), returns the correct amount earned by a dart landing in that point.
Go through the setup instructions for Javascript to install the necessary dependencies:
https://exercism.io/tracks/javascript/installation
Please cd
into exercise directory before running all below commands.
Install assignment dependencies:
$ npm install
Execute the tests with:
$ npm test
In the test suites all tests but the first have been skipped.
Once you get a test passing, you can enable the next one by changing xtest
to
test
.
Once you have a solution ready, you can submit it using:
exercism submit darts.js
It's possible to submit an incomplete solution so you can see how others have completed the exercise.
Inspired by an exercise created by a professor Della Paolera in Argentina
import { score } from './darts';
describe('Darts', () => {
test('Missed target', () => {
expect(score(-9, 9)).toEqual(0);
});
xtest('On the outer circle', () => {
expect(score(0, 10)).toEqual(1);
});
xtest('On the middle circle', () => {
expect(score(-5, 0)).toEqual(5);
});
xtest('On the inner circle', () => {
expect(score(0, -1)).toEqual(10);
});
xtest('Exactly on centre', () => {
expect(score(0, 0)).toEqual(10);
});
xtest('Near the centre', () => {
expect(score(-0.1, -0.1)).toEqual(10);
});
xtest('Just within the inner circle', () => {
expect(score(0.7, 0.7)).toEqual(10);
});
xtest('Just outside the inner circle', () => {
expect(score(0.8, -0.8)).toEqual(5);
});
xtest('Just within the middle circle', () => {
expect(score(-3.5, 3.5)).toEqual(5);
});
xtest('Just outside the middle circle', () => {
expect(score(-3.6, -3.6)).toEqual(1);
});
xtest('Just within the outer circle', () => {
expect(score(-7.0, 7.0)).toEqual(1);
});
xtest('Just outside the outer circle', () => {
expect(score(7.1, -7.1)).toEqual(0);
});
xtest('Asymmetric position between the inner and middle circles', () => {
expect(score(0.5, -4)).toEqual(5);
});
});
export const score = (x, y) => {
const dartRadius = Math.sqrt(Math.pow(x, 2) + Math.pow(y, 2));
const DIMENSIONS = {
outer: 10,
middle: 5,
inner: 1,
};
const POINTS = {
outer: 1,
middle: 5,
inner: 10,
};
if (dartRadius <= DIMENSIONS.inner) return POINTS.inner;
if (dartRadius <= DIMENSIONS.middle) return POINTS.middle;
if (dartRadius <= DIMENSIONS.outer) return POINTS.outer;
return 0;
};
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