Sorting Algorithms In Java

Posted by Mark Henry on May 19th, 2021

In this tutorial, we'll look at sorting algorithms in Java.

A sorting algorithm is one that arranges a set of elements in a specified order

What is the Definition of a Sorting Algorithm?

A Sorting Algorithm rearranges the members of an array or list based on a comparison operator also on elements. In the respective data structure, the comparison operator is employed to determine the new order of elements

In Java, there are several different sorting algorithms.

Different sorting algorithms exist, and not all of them are equally efficient. We'll look into their time complexities to compare them and discover which one performs the best.

1. Insertion Sort
2. Bubble Sort
3. Selection Sort
4. Merge Sort
5. Heapsort

1. Sorting by insertion

The idea behind Insertion Sort is to break the range into sorted and unsorted subarrays. The categorized section begins at the beginning of period 1 and corresponds to the array's first (left side) component. Every iteration, we travel through the array, expanding the categorized section of the array by one component. When we expand, the new element is placed in the sorted sub-array. We do this by shifting all of the parts to the right until we discover that the initial component does not need to be changed.

The algorithm is as follows:

Start

Repeat steps 2–4 until you reach the end of the array.

Compare the element at index I to the one before it. If it's smaller, go back to step 3 and try again.

Continue moving elements from the array's "sorted" section until the key's right place is discovered.

2. Sort by bubbles

If the bubble is not in the correct sequence, it will work by changing components in its immediate vicinity. This process is continued until all of the array's components are in the correct order. We know that if we complete the iteration without swaps, all items compared to their neighboring elements, and, by extension, the entire array will be in the desired order. The Bubble Sort algorithm was developed because numbers like “bubble up” into the “ground.” If you walk through the instance again after a certain length of time (4 is a good example), you'll see that the number progressively goes to the right.

The algorithm is as follows:

Start

Make two loops - one inner and one exterior.

Rep the stages until the outer loop is depleted.

Swap the values of the two items if the current element in the inner loop is smaller than the next element.

3. Sorting by Selection

Sorting Out Selection Sort divides the array into an array of unsorted classes. This time, the sorting subarray is created by exchanging the smallest element of the unsorted subarray at the end of the sorted array.

The algorithm is as follows:

Start

Make two loops: one inner and one exterior.

Rep these processes until you've identified the bare minimum of elements.

Assign a minimum value to the element identified by the outer loop variable.

Change the value of the minimum element to the current element if the current element in the inner loop is smaller than the indicated minimum element.

Replace the value of the minimal element with the value of the outer loop variable's element.

4. Sort by Merge

Merge sort is one of the most versatile Java sorting algorithms ever devised (yes, no kidding). It sorts elements in an array using the divide and conquers approach. It's also a stable sort, which means it won't modify the order of the array's initial items in relation to each other. The underlying approach divides the array into smaller parts until segments with just two (or one) items are found. These segments' elements have now been sorted, and the segments have been consolidated to make bigger segments. This procedure is repeated until the full array has been sorted.

5. Heap Sort

Heap sort is one of the most essential sorting methods in Java that everybody interested in sorting should master. It blends the notions of a tree with sorting, effectively strengthening the use of both. A heap is a full binary search tree in which objects are kept in a certain order based on the need. Every child of the root must be bigger than the root itself, and a min-heap includes the minimal element at the root. Following that, the children must be greater than these children, and so forth. A max-heap, on the other hand, has the maximum element at the root. The heap is kept in an array for sorting, with the left child at index 2 * I + 1 and the right child at index 2 * I + 2 for each parent node at index i.

With the elements of the unsorted array, a max heap is constructed, and the largest element is retrieved from the array's root and exchanged with the array's final element. The max heap is then rebuilt to obtain the next maximum element. This method is repeated until the heap contains just one node.