refactor: cleanup CocktailShakerSort (#5317)

This commit is contained in:
Alex Klymenko
2024-08-11 19:55:11 +02:00
committed by GitHub
parent 554b6cf006
commit 66bfaff807
2 changed files with 65 additions and 101 deletions

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@ -1,57 +1,81 @@
package com.thealgorithms.sorts;
/**
* CocktailShakerSort class implements the Cocktail Shaker Sort algorithm,
* which is a bidirectional bubble sort. It sorts the array by passing
* through it back and forth, progressively moving the largest elements
* to the end and the smallest elements to the beginning.
*
* @author Mateus Bizzo (https://github.com/MattBizzo)
* @author Podshivalov Nikita (https://github.com/nikitap492)
*/
class CocktailShakerSort implements SortAlgorithm {
/**
* This method implements the Generic Cocktail Shaker Sort
* Sorts the given array using the Cocktail Shaker Sort algorithm.
*
* @param array The array to be sorted Sorts the array in increasing order
* @param <T> The type of elements in the array, which must be comparable
* @param array The array to be sorted
* @return The sorted array
*/
@Override
public <T extends Comparable<T>> T[] sort(T[] array) {
int length = array.length;
int left = 0;
int right = length - 1;
int swappedLeft;
int swappedRight;
while (left < right) {
// front
swappedRight = 0;
for (int i = left; i < right; i++) {
if (SortUtils.less(array[i + 1], array[i])) {
SortUtils.swap(array, i, i + 1);
swappedRight = i;
}
}
// back
right = swappedRight;
swappedLeft = length - 1;
for (int j = right; j > left; j--) {
if (SortUtils.less(array[j], array[j - 1])) {
SortUtils.swap(array, j - 1, j);
swappedLeft = j;
}
}
left = swappedLeft;
public <T extends Comparable<T>> T[] sort(final T[] array) {
if (array.length == 0) {
return array;
}
int left = 0;
int right = array.length - 1;
while (left < right) {
right = performForwardPass(array, left, right);
left = performBackwardPass(array, left, right);
}
return array;
}
// Driver Program
public static void main(String[] args) {
// Integer Input
Integer[] integers = {4, 23, 6, 78, 1, 54, 231, 9, 12};
CocktailShakerSort shakerSort = new CocktailShakerSort();
/**
* Performs a forward pass through the array, moving larger elements to the end.
*
* @param <T> The type of elements in the array, which must be comparable
* @param array The array being sorted
* @param left The current left boundary of the sorting area
* @param right The current right boundary of the sorting area
* @return The index of the last swapped element during this pass
*/
private <T extends Comparable<T>> int performForwardPass(final T[] array, final int left, final int right) {
int lastSwappedIndex = left;
// Output => 1 4 6 9 12 23 54 78 231
SortUtils.print(shakerSort.sort(integers));
for (int i = left; i < right; i++) {
if (SortUtils.less(array[i + 1], array[i])) {
SortUtils.swap(array, i, i + 1);
lastSwappedIndex = i;
}
}
// String Input
String[] strings = {"c", "a", "e", "b", "d"};
SortUtils.print(shakerSort.sort(strings));
return lastSwappedIndex;
}
/**
* Performs a backward pass through the array, moving smaller elements to the beginning.
*
* @param <T> The type of elements in the array, which must be comparable
* @param array The array being sorted
* @param left The current left boundary of the sorting area
* @param right The current right boundary of the sorting area
* @return The index of the last swapped element during this pass
*/
private <T extends Comparable<T>> int performBackwardPass(final T[] array, final int left, final int right) {
int lastSwappedIndex = right;
for (int i = right; i > left; i--) {
if (SortUtils.less(array[i], array[i - 1])) {
SortUtils.swap(array, i - 1, i);
lastSwappedIndex = i;
}
}
return lastSwappedIndex;
}
}