26 lines
607 B
Markdown
26 lines
607 B
Markdown
---
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title: Array ranking
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type: snippet
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language: javascript
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tags: [array,math]
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author: chalarangelo
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cover: eagle
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dateModified: 2022-04-13T05:00:00-04:00
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---
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Calculates the ranking of an array based on a comparator function.
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- Use `Array.prototype.map()` and `Array.prototype.filter()` to map each element to a rank using the provided comparator function.
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```js
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const ranking = (arr, compFn) =>
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arr.map(a => arr.filter(b => compFn(a, b)).length + 1);
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```
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```js
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ranking([8, 6, 9, 5], (a, b) => a < b);
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// [2, 3, 1, 4]
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ranking(['c', 'a', 'b', 'd'], (a, b) => a.localeCompare(b) > 0);
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// [3, 1, 2, 4]
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```
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