/*
 * Copyright (c) 2017 Kotlin Algorithm Club
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

package io.uuddlrlrba.ktalgs.sorts

/**
 * Selection sort is a simple sorting algorithm dividing the input list into two parts: the sublist of items already
 * sorted, which is built up from left to right at the front (left) of the list, and the sublist of items remaining
 * to be sorted that occupy the rest of the list. Initially, the sorted sublist is empty and the unsorted sublist
 * is the entire input list. The algorithm proceeds by finding the smallest (or largest, depending on sorting order)
 * element in the unsorted sublist, exchanging (swapping) it with the leftmost unsorted element
 * (putting it in sorted order), and moving the sublist boundaries one element to the right.
 */
@ComparisonSort
@UnstableSort
class SelectionSort : AbstractSortStrategy() {
    public override fun<T : Comparable<T>> perform(arr: Array<T>) {
        for (i in arr.indices) {
            var min = i
            for (j in i + 1 until arr.size) {
                if (arr[j] < arr[min]) {
                    min = j
                }
            }
            if (min != i) arr.exch(min, i)
        }
    }
}