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>
141 lines
2.5 KiB
Markdown
141 lines
2.5 KiB
Markdown
---
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id: 5a23c84252665b21eecc802a
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title: Stream Merge
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challengeType: 5
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forumTopicId: 302326
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dashedName: stream-merge
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---
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# --description--
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Write a function that takes multiple sorted arrays of items, and returns one array of sorted items.
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# --hints--
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`mergeLists` should be a function.
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```js
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assert(typeof mergeLists == 'function');
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```
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`mergeLists([[1, 3, 5, 9, 10], [2, 4, 6, 7, 8]])` should return an array.
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```js
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assert(
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Array.isArray(
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mergeLists([
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[1, 3, 5, 9, 10],
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[2, 4, 6, 7, 8]
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])
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)
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);
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```
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`mergeLists([[1, 3, 5, 9, 10], [2, 4, 6, 7, 8]])` should return `[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]`.
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```js
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assert.deepEqual(
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mergeLists([
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[1, 3, 5, 9, 10],
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[2, 4, 6, 7, 8]
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]),
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[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
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);
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```
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`mergeLists([[1, 4, 7, 10], [2, 5, 8, 11], [3, 6, 9, 12]])` should return `[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]`.
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```js
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assert.deepEqual(
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mergeLists([
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[1, 4, 7, 10],
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[2, 5, 8, 11],
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[3, 6, 9, 12]
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]),
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[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]
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);
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```
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`mergeLists([[1, 3, 9, 14, 15, 17, 28], [7, 8, 14, 14, 23, 26, 28, 29, 30], [9, 23, 25, 29]])` should return `[1, 3, 7, 8, 9, 9, 14, 14, 14, 15, 17, 23, 23, 25, 26, 28, 28, 29, 29, 30]`.
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```js
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assert.deepEqual(
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mergeLists([
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[1, 3, 9, 14, 15, 17, 28],
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[7, 8, 14, 14, 23, 26, 28, 29, 30],
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[9, 23, 25, 29]
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]),
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[1, 3, 7, 8, 9, 9, 14, 14, 14, 15, 17, 23, 23, 25, 26, 28, 28, 29, 29, 30]
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);
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```
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`mergeLists([[3, 14, 15], [2, 17, 18], [], [2, 3, 5, 7]])` should return `[2, 2, 3, 3, 5, 7, 14, 15, 17, 18]`.
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```js
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assert.deepEqual(mergeLists([[3, 14, 15], [2, 17, 18], [], [2, 3, 5, 7]]), [
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2,
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2,
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3,
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3,
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5,
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7,
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14,
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15,
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17,
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18
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]);
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```
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`mergeLists([[1, 19, 1999], [17, 33, 2999, 3000], [8, 500, 3999]])` should return `[1, 8, 17, 19, 33, 500, 1999, 2999, 3000, 3999]`.
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```js
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assert.deepEqual(
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mergeLists([
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[1, 19, 1999],
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[17, 33, 2999, 3000],
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[8, 500, 3999]
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]),
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[1, 8, 17, 19, 33, 500, 1999, 2999, 3000, 3999]
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);
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```
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# --seed--
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## --seed-contents--
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```js
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function mergeLists(lists) {
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}
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```
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# --solutions--
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```js
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function mergeLists(lists) {
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function merge(l1, l2) {
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var result = [],
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i = 0,
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j = 0;
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while (l1.length && l2.length) {
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if (l1[i] <= l2[j]) {
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result.push(l1.shift());
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} else {
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result.push(l2.shift());
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}
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}
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result.push.apply(result, l1);
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result.push.apply(result, l2);
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return result;
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}
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var result = lists[0];
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for (var i = 1; i < lists.length; i++) {
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result = merge(result, lists[i]);
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}
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return result;
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}
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```
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