Java/Sorts/ShellSort.java at master · iDev-git/Java · GitHub

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package Sorts;

import static Sorts.SortUtils.*;

public class ShellSort implements SortAlgorithm {

/**

* This method implements Generic Shell Sort.

* @param array the array to be sorted

@Override

public <T extends Comparable<T>> T[] sort(T[] array) {

int length = array.length;

int gap = 1;

/* Calculate gap for optimization purpose */

while (gap < length / 3) {

gap = 3 * gap + 1;

}

for (; gap > 0; gap /= 3) {

for (int i = gap; i < length; i++) {

int j;

T temp = array[i];

for (j = i; j >= gap && less(temp, array[j - gap]); j -= gap) {

array[j] = array[j - gap];

}

array[j] = temp;

}

return array;

}

/* Driver Code */

public static void main(String[] args) {

Integer[] toSort = {4, 23, 6, 78, 1, 54, 231, 9, 12};

ShellSort sort = new ShellSort();

print(sort.sort(toSort));

}