Given a string representing a matrix of numbers, return the rows and columns of that matrix.
So given a string with embedded newlines like:
9 8 7
5 3 2
6 6 7
representing this matrix:
1 2 3
|---------
1 | 9 8 7
2 | 5 3 2
3 | 6 6 7
your code should be able to spit out:
The rows for our example matrix:
And its columns:
Go through the setup instructions for Javascript to install the necessary dependencies:
https://exercism.io/tracks/javascript/installation
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
.
Warmup to the saddle-points
warmup. http://jumpstartlab.com
It's possible to submit an incomplete solution so you can see how others have completed the exercise.
import { Matrix } from './matrix';
describe('Matrix', () => {
test('extract row from one number matrix', () => {
expect(new Matrix('1').rows[0]).toEqual([1]);
});
xtest('can extract row', () => {
expect(new Matrix('1 2\n3 4').rows[1]).toEqual([3, 4]);
});
xtest('extract row where numbers have different widths', () => {
expect(new Matrix('1 2\n10 20').rows[1]).toEqual([10, 20]);
});
xtest('can extract row from non-square matrix', () => {
expect(new Matrix('1 2 3\n4 5 6\n7 8 9\n8 7 6').rows[2]).toEqual([7, 8, 9]);
});
xtest('extract column from one number matrix', () => {
expect(new Matrix('1').columns[0]).toEqual([1]);
});
xtest('can extract column', () => {
expect(new Matrix('1 2 3\n4 5 6\n7 8 9').columns[2]).toEqual([3, 6, 9]);
});
xtest('can extract column from non-square matrix', () => {
expect(new Matrix('1 2 3\n4 5 6\n7 8 9\n8 7 6').columns[2]).toEqual([3, 6, 9, 6]);
});
xtest('extract column where numbers have different widths', () => {
expect(new Matrix('89 1903 3\n18 3 1\n9 4 800').columns[1]).toEqual([1903, 3, 4]);
});
});
export class Matrix {
constructor(matrix_string) {
this.data = [];
for (const row of matrix_string.split("\n")) {
this.data.push(row.split(" ").map(Number));
}
}
get rows() {
return this.data;
}
get columns() {
let columns = [];
for (let i = 0; i < this.data.length; i++) {
columns.push(this.data.map(function(row) {return row[i];}))
}
return columns;
}
}
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