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Recursive Bubble Sort

Bubble sort is a simple sorting algorithm that repeatedly steps through the list to be sorted, compares adjacent elements and swaps them if they are in the wrong order. The pass through the list is repeated until the list is sorted.

The Recursive Bubble Sort is a variation of the traditional Bubble Sort algorithm. Bubble Sort is a simple comparison-based sorting algorithm that repeatedly steps through the list to be sorted, compares adjacent elements, and swaps them if they are in the wrong order. The process is repeated until the entire list is sorted.

Recursive Bubble Sort, as the name suggests, employs a recursive approach to perform the sorting. In the recursive version, we perform one pass of the Bubble Sort and then call the recursive function on the reduced subarray without the last element (since it is already in its correct position). This process continues until the entire array is sorted.

Problem Statement

Given an array of integers, we want to sort it in ascending order using Recursive Bubble Sort.

Example

Let's take an example to illustrate the Recursive Bubble Sort process:

Given Array: [5, 2, 8, 1, 6]

  1. Initial array: [5, 2, 8, 1, 6]
  2. Recursive pass 1: [2, 5, 1, 6, 8]
  3. Recursive pass 2: [2, 1, 5, 6, 8]
  4. Recursive pass 3: [1, 2, 5, 6, 8]

The array is now sorted in ascending order.

Pseudocode

The pseudocode for Recursive Bubble Sort is as follows:

// Function for Recursive Bubble Sort
recursive_bubble_sort(record[], size):
    if size <= 0:
        return

    for i = 0 to size - 2:
        if record[i] > record[i + 1]:
            swap record[i] and record[i + 1]

    recursive_bubble_sort(record, size - 1)

Algorithm Explanation:

  1. Start with the given array and its size.
  2. Call the recursive_bubble_sort function with the array and its size.
  3. In the recursive_bubble_sort function, check if the size of the array is less than or equal to 0. If so, return (base case).
  4. Run a loop from 0 to size - 2 (size - 1 is excluded to avoid out-of-bounds access).
  5. Inside the loop, compare adjacent elements at indices i and i + 1. If the current element is greater than the next element, swap them.
  6. After completing one pass of the Bubble Sort, call the recursive_bubble_sort function recursively with the array and size - 1, effectively excluding the last element from further sorting.
  7. The recursion continues until the size becomes 1, and the array is sorted.

Explanation of the Code:

  1. The code starts with the main function where the initial array record is defined.
  2. The size of the array is calculated using sizeof(record) / sizeof(record[0]).
  3. The display function is defined to print the elements of the array.
  4. The unsorted array is displayed before sorting using display(record, size).
  5. The bubble_sort function is called to sort the array.
  6. The sorted array is displayed after sorting using display(record, size).

Program Solution

//C Program
//Recursive Bubble Sort
#include <stdio.h>

//Display array elements
void display(int record[], int size)
{
	for (int i = 0; i < size; ++i)
	{
		printf("%d ", record[i]);
	}
	printf("\n");
}
//Perform bubble sort in given array
void bubble_sort(int record[], int size)
{
	if (size <= 0)
	{
		//When have no more than one element
		return;
	}
	int temp = 0;
	for (int i = 0; i < size - 1; ++i)
	{
		//Compare two adjacent elements
		if (record[i] > record[i + 1])
		{
			//When need to swap two adjacent elements
			temp = record[i];
			record[i] = record[i + 1];
			record[i + 1] = temp;
		}
	}
	bubble_sort(record, size - 1);
}
int main()
{
	//Assume given array elements
	int record[] = {
		2 , 8 , 1 , 5 , 0 , 9 , 3 , 7 , 2
	};
	//Get the size of array 
	int size = sizeof(record) / sizeof(record[0]);
	//Before sort
	display(record, size);
	bubble_sort(record, size);
	//After sort
	display(record, size);
	return 0;
}

Output

2 8 1 5 0 9 3 7 2
0 1 2 2 3 5 7 8 9
//Java Program
//Recursive Bubble Sort
class MySort
{
	//Display array elements
	public void display(int[] record, int size)
	{
		for (int i = 0; i < size; ++i)
		{
			System.out.print(" " + record[i]);
		}
		System.out.print("\n");
	}
	//Perform bubble sort in given array
	public void bubble_sort(int[] record, int size)
	{
		if (size <= 0)
		{
			//When have no more than one element
			return;
		}
		int temp = 0;
		for (int i = 0; i < size - 1; ++i)
		{
			//Compare two adjacent elements
			if (record[i] > record[i + 1])
			{
				//When need to swap two adjacent elements
				temp = record[i];
				record[i] = record[i + 1];
				record[i + 1] = temp;
			}
		}
		bubble_sort(record, size - 1);
	}
	public static void main(String[] args)
	{
		MySort obj = new MySort();
		//Assume given array elements
		int[] record = {
			2,
			8,
			1,
			5,
			0,
			9,
			3,
			7,
			2
		};
		//Get the size of array 
		int size = record.length;
		//Before sort
		obj.display(record, size);
		obj.bubble_sort(record, size);
		//After sort
		obj.display(record, size);
	}
}

Output

 2 8 1 5 0 9 3 7 2
 0 1 2 2 3 5 7 8 9
//Include header file
#include <iostream>
using namespace std;

//C++ Program
//Recursive Bubble Sort
class MySort
{
	public:
		//Display array elements
		void display(int record[], int size)
		{
			for (int i = 0; i < size; ++i)
			{
				cout << " " << record[i];
			}
			cout << "\n";
		}
	//Perform bubble sort in given array
	void bubble_sort(int record[], int size)
	{
		if (size <= 0)
		{
			//When have no more than one element
			return;
		}
		int temp = 0;
		for (int i = 0; i < size - 1; ++i)
		{
			//Compare two adjacent elements
			if (record[i] > record[i + 1])
			{
				//When need to swap two adjacent elements
				temp = record[i];
				record[i] = record[i + 1];
				record[i + 1] = temp;
			}
		}
		this->bubble_sort(record, size - 1);
	}
};
int main()
{
	MySort obj = MySort();
	int record[] = {
		2 , 8 , 1 , 5 , 0 , 9 , 3 , 7 , 2
	};
	//Get the size of array 
	int size = sizeof(record) / sizeof(record[0]);
	//Before sort
	obj.display(record, size);
	obj.bubble_sort(record, size);
	//After sort
	obj.display(record, size);
	return 0;
}

Output

 2 8 1 5 0 9 3 7 2
 0 1 2 2 3 5 7 8 9
//Include namespace system
using System;
//C# Program
//Recursive Bubble Sort
class MySort
{
	//Display array elements
	public void display(int[] record, int size)
	{
		for (int i = 0; i < size; ++i)
		{
			Console.Write(" " + record[i]);
		}
		Console.Write("\n");
	}
	//Perform bubble sort in given array
	public void bubble_sort(int[] record, int size)
	{
		if (size <= 0)
		{
			//When have no more than one element
			return;
		}
		int temp = 0;
		for (int i = 0; i < size - 1; ++i)
		{
			//Compare two adjacent elements
			if (record[i] > record[i + 1])
			{
				//When need to swap two adjacent elements
				temp = record[i];
				record[i] = record[i + 1];
				record[i + 1] = temp;
			}
		}
		bubble_sort(record, size - 1);
	}
	public static void Main(String[] args)
	{
		MySort obj = new MySort();
		int[] record = {
			2 , 8 , 1 , 5 , 0 , 9 , 3 , 7 , 2
		};
		//Get the size of array 
		int size = record.Length;
		//Before sort
		obj.display(record, size);
		obj.bubble_sort(record, size);
		//After sort
		obj.display(record, size);
	}
}

Output

 2 8 1 5 0 9 3 7 2
 0 1 2 2 3 5 7 8 9
<?php
//Php Program
//Recursive Bubble Sort
class MySort
{
	//Display array elements
	public	function display( $record, $size)
	{
		for ($i = 0; $i < $size; ++$i)
		{
			echo " ". $record[$i];
		}
		echo "\n";
	}
	//Perform bubble sort in given array
	public	function bubble_sort( & $record, $size)
	{
		if ($size <= 0)
		{
			//When have no more than one element
			return;
		}
		$temp = 0;
		for ($i = 0; $i < $size - 1; ++$i)
		{
			//Compare two adjacent elements
			if ($record[$i] > $record[$i + 1])
			{
				//When need to swap two adjacent elements
				$temp = $record[$i];
				$record[$i] = $record[$i + 1];
				$record[$i + 1] = $temp;
			}
		}
		$this->bubble_sort($record, $size - 1);
	}
}

function main()
{
	$obj = new MySort();
	//Assume given array elements
	$record = array(2, 8, 1, 5, 0, 9, 3, 7, 2);
	//Get the size of array 
	$size = count($record);
	//Before sort
	$obj->display($record, $size);
	$obj->bubble_sort($record, $size);
	//After sort
	$obj->display($record, $size);
}
main();

Output

 2 8 1 5 0 9 3 7 2
 0 1 2 2 3 5 7 8 9
//Node Js Program
//Recursive Bubble Sort
class MySort
{
	//Display array elements
	display(record, size)
	{
		for (var i = 0; i < size; ++i)
		{
			process.stdout.write(" " + record[i]);
		}
		process.stdout.write("\n");
	}
	//Perform bubble sort in given array
	bubble_sort(record, size)
	{
		if (size <= 0)
		{
			//When have no more than one element
			return;
		}
		var temp = 0;
		for (var i = 0; i < size - 1; ++i)
		{
			//Compare two adjacent elements
			if (record[i] > record[i + 1])
			{
				//When need to swap two adjacent elements
				temp = record[i];
				record[i] = record[i + 1];
				record[i + 1] = temp;
			}
		}
		this.bubble_sort(record, size - 1);
	}
}

function main()
{
	var obj = new MySort();
	//Assume given array elements
	var record = [2, 8, 1, 5, 0, 9, 3, 7, 2];
	//Get the size of array 
	var size = record.length;
	//Before sort
	obj.display(record, size);
	obj.bubble_sort(record, size);
	//After sort
	obj.display(record, size);
}
main();

Output

 2 8 1 5 0 9 3 7 2
 0 1 2 2 3 5 7 8 9
# Python 3 Program
# Recursive Bubble Sort
class MySort :
	# Display array elements
	def display(self, record, size) :
		i = 0
		while (i < size) :
			print(" ", record[i], end = "")
			i += 1
		
		print("\n", end = "")
	
	# Perform bubble sort in given array
	def bubble_sort(self, record, size) :
		if (size <= 0) :
			# When have no more than one element
			return
		
		temp = 0
		i = 0
		while (i < size - 1) :
			# Compare two adjacent elements
			if (record[i] > record[i + 1]) :
				# When need to swap two adjacent elements
				temp = record[i]
				record[i] = record[i + 1]
				record[i + 1] = temp
			
			i += 1
		
		self.bubble_sort(record, size - 1)
	

def main() :
	obj = MySort()
	# Assume given array elements
	record = [2, 8, 1, 5, 0, 9, 3, 7, 2]
	# Get the size of array 
	size = len(record)
	# Before sort
	obj.display(record, size)
	obj.bubble_sort(record, size)
	# After sort
	obj.display(record, size)

if __name__ == "__main__": main()

Output

  2  8  1  5  0  9  3  7  2
  0  1  2  2  3  5  7  8  9
# Ruby Program
# Recursive Bubble Sort
class MySort

	# Display array elements
	def display(record, size)
	
		i = 0
		while (i < size)
		
			print(" ", record[i])
			i += 1
		end
		print("\n")
	end
	# Perform bubble sort in given array
	def bubble_sort(record, size)
	
		if (size <= 0)
		
			# When have no more than one element
			return
		end
		temp = 0
		i = 0
		while (i < size - 1)
		
			# Compare two adjacent elements
			if (record[i] > record[i + 1])
			
				# When need to swap two adjacent elements
				temp = record[i]
				record[i] = record[i + 1]
				record[i + 1] = temp
			end
			i += 1
		end
		self.bubble_sort(record, size - 1)
	end
end
def main()

	obj = MySort.new()
	# Assume given array elements
	record = [2, 8, 1, 5, 0, 9, 3, 7, 2]
	# Get the size of array 
	size = record.length
	# Before sort
	obj.display(record, size)
	obj.bubble_sort(record, size)
	# After sort
	obj.display(record, size)
end
main()

Output

 2 8 1 5 0 9 3 7 2
 0 1 2 2 3 5 7 8 9

//Scala Program
//Recursive Bubble Sort
class MySort
{
	//Display array elements
	def display(record: Array[Int], size: Int): Unit = {
		var i: Int = 0;
		while (i < size)
		{
			print(" " + record(i));
			i += 1;
		}
		print("\n");
	}
	//Perform bubble sort in given array
	def bubble_sort(record: Array[Int], size: Int): Unit = {
		if (size <= 0)
		{
			//When have no more than one element
			return;
		}
		var temp: Int = 0;
		var i: Int = 0;
		while (i < size - 1)
		{
			//Compare two adjacent elements
			if (record(i) > record(i + 1))
			{
				//When need to swap two adjacent elements
				temp = record(i);
				record(i) = record(i + 1);
				record(i + 1) = temp;
			}
			i += 1;
		}
		bubble_sort(record, size - 1);
	}
}
object Main
{
	def main(args: Array[String]): Unit = {
		var obj: MySort = new MySort();
		//Assume given array elements
		var record: Array[Int] = Array(2, 8, 1, 5, 0, 9, 3, 7, 2);
		//Get the size of array 
		var size: Int = record.length;
		//Before sort
		obj.display(record, size);
		obj.bubble_sort(record, size);
		//After sort
		obj.display(record, size);
	}
}

Output

 2 8 1 5 0 9 3 7 2
 0 1 2 2 3 5 7 8 9
//Swift Program
//Recursive Bubble Sort
class MySort
{
	//Display array elements
	func display(_ record: [Int], _ size: Int)
	{
		var i: Int = 0;
		while (i < size)
		{
			print(" ", record[i], terminator: "");
			i += 1;
		}
		print("\n", terminator: "");
	}
	//Perform bubble sort in given array
	func bubble_sort(_ record: inout[Int], _ size: Int)
	{
		if (size <= 0)
		{
			//When have no more than one element
			return;
		}
		var temp: Int = 0;
		var i: Int = 0;
		while (i < size - 1)
		{
			//Compare two adjacent elements
			if (record[i] > record[i + 1])
			{
				//When need to swap two adjacent elements
				temp = record[i];
				record[i] = record[i + 1];
				record[i + 1] = temp;
			}
			i += 1;
		}
		self.bubble_sort(&record, size - 1);
	}
}
func main()
{
	let obj: MySort = MySort();
	//Assume given array elements
	var record: [Int] = [2, 8, 1, 5, 0, 9, 3, 7, 2];
	//Get the size of array 
	let size: Int = record.count;
	//Before sort
	obj.display(record, size);
	obj.bubble_sort(&record, size);
	//After sort
	obj.display(record, size);
}
main();

Output

  2  8  1  5  0  9  3  7  2
  0  1  2  2  3  5  7  8  9

Resultant Output Explanation:

For the given input array [2, 8, 1, 5, 0, 9, 3, 7, 2], the output of the code will be:

Before sort: 2 8 1 5 0 9 3 7 2
After sort: 0 1 2 2 3 5 7 8 9

Time Complexity

The time complexity of Recursive Bubble Sort is the same as that of the traditional Bubble Sort, which is O(n^2) in the worst case. The worst case occurs when the array is sorted in reverse order, and every element needs to be compared and swapped in each pass. However, the average case time complexity is also O(n^2). Although Recursive Bubble Sort provides an interesting recursive approach, it doesn't improve the time complexity of the algorithm. Therefore, it is considered inefficient for large arrays and is mainly used for educational purposes or when dealing with very small datasets.

Last updated on by Kalkicode




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