C++ Program for Recursive Bubble Sort?

In this section we will see another approach of famous bubble sort technique. We have used bubble sort in iterative manner. But here we will see recursive approach of the bubble sort. The recursive bubble sort algorithm is look like this.

Algorithm

bubbleRec(arr, n)

begin
   if n = 1, return
   for i in range 1 to n-2, do
      if arr[i] > arr[i+1], then
         exchange arr[i] and arr[i+1]
      end if
   done
   bubbleRec(arr, n-1)
end

Example

 Live Demo

#include<iostream>
using namespace std;
void recBubble(int arr[], int n){
   if (n == 1)
      return;
   for (int i=0; i<n-1; i++) //for each pass p
      if (arr[i] > arr[i+1]) //if the current element is greater than next one
   swap(arr[i], arr[i+1]); //swap elements
   recBubble(arr, n-1);
}
main() {
   int data[] = {54, 74, 98, 154, 98, 32, 20, 13, 35, 40};
   int n = sizeof(data)/sizeof(data[0]);
   cout << "Sorted Sequence ";
   recBubble(data, n);
   for(int i = 0; i <n;i++){
      cout << data[i] << " ";
   }
}

Output

Sorted Sequence 13 20 32 35 40 54 74 98 98 154