ee1e8abd87
* feat(tools): add seed/solution restore script * chore(curriculum): remove empty sections' markers * chore(curriculum): add seed + solution to Chinese * chore: remove old formatter * fix: update getChallenges parse translated challenges separately, without reference to the source * chore(curriculum): add dashedName to English * chore(curriculum): add dashedName to Chinese * refactor: remove unused challenge property 'name' * fix: relax dashedName requirement * fix: stray tag Remove stray `pre` tag from challenge file. Signed-off-by: nhcarrigan <nhcarrigan@gmail.com> Co-authored-by: nhcarrigan <nhcarrigan@gmail.com>
118 lines
2.0 KiB
Markdown
118 lines
2.0 KiB
Markdown
---
|
|
id: 594810f028c0303b75339ad8
|
|
title: Zig-zag matrix
|
|
challengeType: 5
|
|
forumTopicId: 302348
|
|
dashedName: zig-zag-matrix
|
|
---
|
|
|
|
# --description--
|
|
|
|
A 'zig-zag' array is a square arrangement of the first $N^2$ integers, where the numbers increase sequentially as you zig-zag along the array's [anti-diagonals](https://en.wiktionary.org/wiki/antidiagonal).
|
|
|
|
For example, for the input `5`, the following result should be produced:
|
|
|
|
<pre>
|
|
0 1 5 6 14
|
|
2 4 7 13 15
|
|
3 8 12 16 21
|
|
9 11 17 20 22
|
|
10 18 19 23 24
|
|
</pre>
|
|
|
|
# --instructions--
|
|
|
|
Write a function that takes the size of the zig-zag matrix, and returns the corresponding matrix as two-dimensional array.
|
|
|
|
# --hints--
|
|
|
|
ZigZagMatrix should be a function.
|
|
|
|
```js
|
|
assert.equal(typeof ZigZagMatrix, 'function');
|
|
```
|
|
|
|
ZigZagMatrix should return array.
|
|
|
|
```js
|
|
assert.equal(typeof ZigZagMatrix(1), 'object');
|
|
```
|
|
|
|
ZigZagMatrix should return an array of nested arrays.
|
|
|
|
```js
|
|
assert.equal(typeof ZigZagMatrix(1)[0], 'object');
|
|
```
|
|
|
|
ZigZagMatrix(1) should return \[[0]].
|
|
|
|
```js
|
|
assert.deepEqual(ZigZagMatrix(1), zm1);
|
|
```
|
|
|
|
ZigZagMatrix(2) should return \[[0, 1], [2, 3]].
|
|
|
|
```js
|
|
assert.deepEqual(ZigZagMatrix(2), zm2);
|
|
```
|
|
|
|
ZigZagMatrix(5) should return specified matrix.
|
|
|
|
```js
|
|
assert.deepEqual(ZigZagMatrix(5), zm5);
|
|
```
|
|
|
|
# --seed--
|
|
|
|
## --after-user-code--
|
|
|
|
```js
|
|
const zm1 = [[0]];
|
|
const zm2 = [[0, 1], [2, 3]];
|
|
const zm5 = [
|
|
[0, 1, 5, 6, 14],
|
|
[2, 4, 7, 13, 15],
|
|
[3, 8, 12, 16, 21],
|
|
[9, 11, 17, 20, 22],
|
|
[10, 18, 19, 23, 24]
|
|
];
|
|
```
|
|
|
|
## --seed-contents--
|
|
|
|
```js
|
|
function ZigZagMatrix(n) {
|
|
|
|
return [[], []];
|
|
}
|
|
```
|
|
|
|
# --solutions--
|
|
|
|
```js
|
|
function ZigZagMatrix(n) {
|
|
const mtx = [];
|
|
for (let i = 0; i < n; i++) {
|
|
mtx[i] = [];
|
|
}
|
|
|
|
let i = 1;
|
|
let j = 1;
|
|
for (let e = 0; e < n * n; e++) {
|
|
mtx[i - 1][j - 1] = e;
|
|
if ((i + j) % 2 === 0) {
|
|
// Even stripes
|
|
if (j < n) j++;
|
|
else i += 2;
|
|
if (i > 1) i--;
|
|
} else {
|
|
// Odd stripes
|
|
if (i < n) i++;
|
|
else j += 2;
|
|
if (j > 1) j--;
|
|
}
|
|
}
|
|
return mtx;
|
|
}
|
|
```
|