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* chore: Switch to Node 20 + Vitest * chore: migrate to vitest mock functions * chore: code style (switch to prettier) * test: re-enable long-running test Seems the switch to Node 20 and Vitest has vastly improved the code's and / or the test's runtime! see #1193 * chore: code style * chore: fix failing tests * Updated Documentation in README.md * Update contribution guidelines to state usage of Prettier * fix: set prettier printWidth back to 80 * chore: apply updated code style automatically * fix: set prettier line endings to lf again * chore: apply updated code style automatically --------- Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com> Co-authored-by: Lars Müller <34514239+appgurueu@users.noreply.github.com>
78 lines
2.5 KiB
JavaScript
78 lines
2.5 KiB
JavaScript
/****************************************************************************
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* Fibonacci Search JavaScript Implementation
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* Author Alhassan Atama Isiaka
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* Version v1.0.0
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* Copyright 2020
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* https://github.com/komputarist
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*
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* This implementation is based on Generalizing the Fibonacci search we
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* define the Fibonacci search of degree K. Like the Fibonacci search,
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* which it reduces to for K = 2, the Fibonacci search of degree K
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* involves only addition and subtraction.
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* Capocelli R.M. (1991) A Generalization of the Fibonacci Search. In:
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* Bergum G.E., Philippou A.N., Horadam A.F. (eds) Applications of Fibonacci
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* Numbers. Springer, Dordrecht. https://doi.org/10.1007/978-94-011-3586-3_9
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*
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* This snippet is free. Feel free to improve on it
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*
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* We define a function fibonacciSearch() that takes an array of numbers,
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* the item (number) to be searched for and the length of the items in the array
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****************************************************************************/
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export const fibonacciSearch = (arr, x, n) => {
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let fib2 = 0 // (K-2)'th Fibonacci Number
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let fib1 = 1 // (K-1)'th Fibonacci Number.
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let fibK = fib2 + fib1 // Kth Fibonacci
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/* We want to store the smallest fibonacci number smaller such that
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number is greater than or equal to n, we use fibK for this */
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while (fibK < n) {
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fib2 = fib1
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fib1 = fibK
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fibK = fib2 + fib1
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}
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// This marks the eliminated range from front
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let offset = -1
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/* while there are elements to be checked. We compare arr[fib2] with x.
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When fibM becomes 1, fib2 becomes 0 */
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while (fibK > 1) {
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// Check if fibK is a valid location
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const i = Math.min(offset + fib2, n - 1)
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/* If x is greater than the value at
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index fib2, Partition the subarray array
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from offset to i */
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if (arr[i] < x) {
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fibK = fib1
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fib1 = fib2
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fib2 = fibK - fib1
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offset = i
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/* If x is greater than the value at
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index fib2, cut the subarray array
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from offset to i */
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} else if (arr[i] > x) {
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fibK = fib2
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fib1 = fib1 - fib2
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fib2 = fibK - fib1
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} else {
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// return index for found element
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return i
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}
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}
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// comparing the last element with x */
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if (fib1 && arr[offset + 1] === x) {
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return offset + 1
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}
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// element not found. return -1
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return -1
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}
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// Example
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// const myArray = [10, 22, 35, 40, 45, 50, 80, 82, 85, 90, 100]
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// const n = myArray.length
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// const x = 90
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// const fibFinder = fibonacciSearch(myArray, x, n)
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