ArraySimpleInsertionSortInplace.java

package org.osgl.util.algo;

import org.osgl.$;

import java.util.Arrays;
import java.util.Comparator;

/**
 * Array insertion sort algorithm. 
 *
 * Use {@link java.util.Arrays#binarySearch(Object[], int, int, Object, java.util.Comparator)}
 * to locate the index to be inserted, and use
 */
public class ArraySimpleInsertionSortInplace<T> extends ArraySortInplaceBase<T> implements ArraySort<T> {

    protected T[] sort0(T[] ts, int from, int to, Comparator<T> comp) {
        for (int i = from + 1; i < to; ++i) {
            T t = ts[i];
            int j = i - from - 1;
            while (j >= 0) {
                if (comp.compare(t, ts[j]) < 0) {
                    j--;
                    continue;
                }
                break;
            }
            j++;
            System.arraycopy(ts, j, ts, j + 1, i - from - j);
            ts[j] = t;
        }
        return ts;
    }

    public static void main(String[] args) {
        Integer[] ia = {5, 4, 3, 2, 1};
        ArraySimpleInsertionSortInplace<Integer> s = new ArraySimpleInsertionSortInplace<Integer>();
        Integer[] a = s.apply(ia, 0, 4, $.F.NATURAL_ORDER);
        System.out.println(Arrays.toString(a));
    }

}