recursive_bubble_sort.cpp File Reference

This is an implementation of a recursive version of the Bubble sort algorithm More...

#include <cassert>
#include <iostream>
#include <vector>
#include <array>
#include <algorithm>

Include dependency graph for recursive_bubble_sort.cpp:

Namespaces
	sorting
	Sorting algorithms.

Functions
template<typename T >
void	sorting::recursive_bubble_sort (std::vector< T > *nums, uint64_t n)
	This is an implementation of the recursive_bubble_sort. A vector is passed to the function which is then dereferenced, so that the changes are reflected in the original vector. It also accepts a second parameter of type int and name n, which is the size of the array. More...
static void	test ()
	Self-test implementations. More...
int	main ()
	Main function. More...

Detailed Description

This is an implementation of a recursive version of the Bubble sort algorithm

Author

Aditya Prakash

The working principle of the Bubble sort algorithm.

Bubble sort is a simple sorting algorithm used to rearrange a set of ascending or descending order elements. Bubble sort gets its name from the fact that data "bubbles" to the top of the dataset.

Algorithm

What is Swap?

Swapping two numbers means that we interchange their values. Often, an additional variable is required for this operation. This is further illustrated in the following:

void swap(int x, int y){ int z = x; x = y; y = z; }

The above process is a typical displacement process. When we assign a value to x, the old value of x is lost. That's why we create a temporary variable z to store the initial value of x. z is further used to assign the initial value of x to y, to complete swapping.

Recursion

While the recursive method does not necessarily have advantages over iterative versions, but it is useful to enhance the understanding of the algorithm and recursion itself. In Recursive Bubble sort algorithm, we firstly call the function on the entire array, and for every subsequent function call, we exclude the last element. This fixes the last element for that sub-array.Formally, for ith iteration, we consider elements up to n-i, where n is the number of elements in the array. Exit condition: n==1; i.e. the sub-array contains only one element.

Complexity Time complexity: O(n) best case; O(n²) average case; O(n²) worst case Space complexity: O(n)

We need to traverse the array n * (n-1) times. However, if the entire array is already sorted, then we need to traverse it only once. Hence, O(n) is the best case complexity

Function Documentation

main()

int main

(

void

)

Main function.

Returns

0 on exit

           { 
    test();  // run self-test implementations
    return 0;
}

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test()

static void test ( )

static

Self-test implementations.

Returns

void

                   {
    // 1st example. Creating an array of type `int`.
    std::cout << "1st test using `int`\n";
    const uint64_t size = 6;
    std::vector<int64_t> arr;
    // populating the array
    arr.push_back(22);
    arr.push_back(46);
    arr.push_back(94);
    arr.push_back(12);
    arr.push_back(37);
    arr.push_back(63);
    // array populating ends
 
    sorting::recursive_bubble_sort(&arr, size);
    assert(std::is_sorted(std::begin(arr), std::end(arr)));
    std::cout << " 1st test passed!\n";
    // printing the array
    for (uint64_t i = 0; i < size; i++) {
        std::cout << arr[i] << ", ";
    }
    std::cout << std::endl;
 
    // 2nd example. Creating an array of type `double`.
    std::cout << "2nd test using doubles\n";
    std::vector<double> double_arr;
 
    // populating the array
    double_arr.push_back(20.4);
    double_arr.push_back(62.7);
    double_arr.push_back(12.2);
    double_arr.push_back(43.6);
    double_arr.push_back(74.1);
    double_arr.push_back(57.9);
    // array populating ends
 
    sorting::recursive_bubble_sort(&double_arr, size);
    assert(std::is_sorted(std::begin(double_arr), std::end(double_arr)));
    std::cout << " 2nd test passed!\n";
    // printing the array
    for (uint64_t i = 0; i < size; i++) {
        std::cout << double_arr[i] << ", ";
    }
    std::cout << std::endl;
 
}