Princeton1/module5/src/main/java/com/hithomelabs/princeton1/module5/Selection.java

package com.hithomelabs.princeton1.module5;


import java.util.Comparator;

public class Selection<E> implements MeasurableSort<E>, MeasurableHelper {

    /*
    * * Selection sort "selects" the smallest element and swaps it with arr[0] of the array
    * * Then proceeds to do the same swapping arr[i] with arr[i:arr.length-1]
    */
    public void sort(E[] arr){
        coreSortLogic(arr, null, null);
    }

    private void coreSortLogic(E[] arr, Comparator<E> cmp, SortingMetaData metaData){
        if (arr ==  null) return;
        Comparable<E>[] arr1 = (Comparable<E>[]) arr;
        for(int i = 0; i < arr1.length - 1; i++){
            int minIndex = i;
            for(int j = i+1; j < arr.length; j ++){
                if (MeasurableHelper.less(arr[j], arr[minIndex], cmp, metaData)) minIndex = j;
            }
            MeasurableHelper.exch(arr, i, minIndex, metaData);
        }
    }

    @Override
    public void sort(E[] arr, Comparator<E> cmp, SortingMetaData metaData) {
        if (metaData != null)
            metaData.startTime();
        coreSortLogic(arr, cmp, metaData);
        if (metaData != null)
            metaData.endTime();
    }

    @Override
    public void sort(E[] arr, Comparator<E> cmp) {
        coreSortLogic(arr, cmp, null);
    }

    @Override
    public String toString() {
        return "Selection Sort";
    }
}