10 lines
302 B
JavaScript
10 lines
302 B
JavaScript
const sortedLastIndexBy = (arr, n, fn) => {
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const isDescending = fn(arr[0]) > fn(arr[arr.length - 1]);
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const val = fn(n);
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const index = arr
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.map(fn)
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.reverse()
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.findIndex(el => (isDescending ? val <= el : val >= el));
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return index === -1 ? 0 : arr.length - index;
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};
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module.exports = sortedLastIndexBy; |