Recursive Selection Sort - GeeksforGeeks

29 Apr, 2022
The Selection Sort algorithm sorts maintain two parts. 
The first part that is already sortedThe second part is yet to be sorted.
The first part that is already sorted
The second part is yet to be sorted.
The algorithm works by repeatedly finding the minimum element (considering ascending order) from the unsorted part and putting it at the end of the sorted part.  
arr[] = 64 25 12 22 11

// Find the minimum element in arr[0...4]
// and place it at beginning
11 25 12 22 64

// Find the minimum element in arr[1...4]
// and place it at beginning of arr[1...4]
11 12 25 22 64

// Find the minimum element in arr[2...4]
// and place it at beginning of arr[2...4]
11 12 22 25 64

// Find the minimum element in arr[3...4]
// and place it at beginning of arr[3...4]
11 12 22 25 64 
We have already discussed Iterative Selection Sort. In this article recursive approach is discussed. The idea of a recursive solution is to one by one increment sorted part and recursively call for the remaining (yet to be sorted) part.
C++
Java
Python3
C#
// Recursive C++ program to sort an array// using selection sort#include <iostream>using namespace std; // Return minimum indexint minIndex(int a[], int i, int j){    if (i == j)        return i;     // Find minimum of remaining elements    int k = minIndex(a, i + 1, j);     // Return minimum of current and remaining.    return (a[i] < a[k])? i : k;} // Recursive selection sort. n is size of a[] and index// is index of starting element.void recurSelectionSort(int a[], int n, int index = 0){    // Return when starting and size are same    if (index == n)       return;     // calling minimum index function for minimum index    int k = minIndex(a, index, n-1);     // Swapping when index and minimum index are not same    if (k != index)       swap(a[k], a[index]);     // Recursively calling selection sort function    recurSelectionSort(a, n, index + 1);} // Driver codeint main(){    int arr[] = {3, 1, 5, 2, 7, 0};    int n = sizeof(arr)/sizeof(arr[0]);     // Calling function    recurSelectionSort(arr, n);     //printing sorted array    for (int i = 0; i<n ; i++)        cout << arr[i] << " ";    cout << endl;    return 0;}
// Recursive Java program to sort an array// using selection sort class Test{    // Return minimum index    static int minIndex(int a[], int i, int j)    {        if (i == j)            return i;              // Find minimum of remaining elements        int k = minIndex(a, i + 1, j);              // Return minimum of current and remaining.        return (a[i] < a[k])? i : k;    }          // Recursive selection sort. n is size of a[] and index    // is index of starting element.    static void recurSelectionSort(int a[], int n, int index)    {                  // Return when starting and size are same        if (index == n)           return;              // calling minimum index function for minimum index        int k = minIndex(a, index, n-1);              // Swapping when index nd minimum index are not same        if (k != index){           // swap           int temp = a[k];           a[k] = a[index];           a[index] = temp;        }        // Recursively calling selection sort function        recurSelectionSort(a, n, index + 1);    }               // Driver method    public static void main(String args[])    {        int arr[] = {3, 1, 5, 2, 7, 0};              // Calling function        recurSelectionSort(arr, arr.length, 0);              //printing sorted array        for (int i = 0; i< arr.length; i++)            System.out.print(arr[i] + " ");    }}
# Recursive Python3 code to sort# an array using selection sort # Return minimum indexdef minIndex( a , i , j ):    if i == j:        return i             # Find minimum of remaining elements    k = minIndex(a, i + 1, j)         # Return minimum of current    # and remaining.    return (i if a[i] < a[k] else k)     # Recursive selection sort. n is# size of a[] and index is index of# starting element.def recurSelectionSort(a, n, index = 0):     # Return when starting and    # size are same    if index == n:        return -1             # calling minimum index function    # for minimum index    k = minIndex(a, index, n-1)         # Swapping when index and minimum    # index are not same    if k != index:        a[k], a[index] = a[index], a[k]             # Recursively calling selection    # sort function    recurSelectionSort(a, n, index + 1)     # Driver codearr = [3, 1, 5, 2, 7, 0]n = len(arr) # Calling functionrecurSelectionSort(arr, n) # printing sorted arrayfor i in arr:    print(i, end = ' ')     # This code is contributed by "Sharad_Bhardwaj".
// Recursive C# program to sort an array// using selection sortusing System; class GFG{    // Return minimum index    static int minIndex(int []a, int i, int j)    {        if (i == j)            return i;             // Find minimum of remaining elements        int k = minIndex(a, i + 1, j);             // Return minimum of current and remaining.        return (a[i] < a[k])? i : k;    }         // Recursive selection sort. n is size of    // a[] and index is index of starting element.    static void recurSelectionSort(int []a, int n,                                   int index)    {                 // Return when starting and size are same        if (index == n)        return;             // calling minimum index function        // for minimum index        int k = minIndex(a, index, n - 1);             // Swapping when index and minimum index        // are not same        if (k != index)        {            // swap            int temp = a[k];            a[k] = a[index];            a[index] = temp;        }                 // Recursively calling selection sort function        recurSelectionSort(a, n, index + 1);    }         // Driver Code    public static void Main(String []args)    {        int []arr = {3, 1, 5, 2, 7, 0};             // Calling function        recurSelectionSort(arr, arr.Length, 0);             //printing sorted array        for (int i = 0; i< arr.Length; i++)            Console.Write(arr[i] + " ");    }} // This code is contributed by Princi Singh
Output:  
0 1 2 3 5 7 
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