74 lines
2.2 KiB
Kotlin
74 lines
2.2 KiB
Kotlin
/*
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* MIT License
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*
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* Copyright (c) 2019 norangebit
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in all
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* copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*
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*/
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package it.norangeb.algorithms.sorting
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object Quicksort : Sorter() {
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override fun <T> sort(array: Array<T>, isLess: (T, T) -> Boolean) {
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sort(array, 0, array.size - 1, isLess)
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}
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private fun <T> sort(array: Array<T>, low: Int, high: Int, isLess: (T, T) -> Boolean) {
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if (low >= high)
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return
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val mid = partitioning(array, low, high, isLess)
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sort(array, low, mid - 1, isLess)
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sort(array, mid + 1, high, isLess)
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}
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private fun <T> partitioning(
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array: Array<T>,
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low: Int,
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high: Int,
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isLess: (T, T) -> Boolean
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): Int {
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var i = low
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var j = high + 1
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while (true) {
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while (isLess(array[++i], array[low]))
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if (i == high) break
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while (isLess(array[low], array[--j]))
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if (j == low) break
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if (i >= j) break
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swap(array, i, j)
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}
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swap(array, low, j)
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return j
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}
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private fun <T> swap(array: Array<T>, i: Int, j: Int) {
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val tmp = array[i]
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array[i] = array[j]
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array[j] = tmp
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}
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} |