Java Program for Recursive Insertion Sort

Last Updated : 14 Mar, 2023

Insertion sort is a simple sorting algorithm that works the way we sort playing cards in our hands.Below is an iterative algorithm for insertion sort

Algorithm

// Sort an arr[] of size n
insertionSort(arr, n) 
    Loop from i = 1 to n-1.
       a) Pick element arr[i] and insert
          it into sorted sequence arr[0..i-1]

Java

// Recursive Java program for insertion sort
 
import java.util.Arrays;
 
public class GFG 
{
    // Recursive function to sort an array using
    // insertion sort
    static void insertionSortRecursive(int arr[], int n)
    {
        // Base case
        if (n <= 1)
            return;
      
        // Sort first n-1 elements
        insertionSortRecursive( arr, n-1 );
      
        // Insert last element at its correct position
        // in sorted array.
        int last = arr[n-1];
        int j = n-2;
      
        /* Move elements of arr[0..i-1], that are
          greater than key, to one position ahead
          of their current position */
        while (j >= 0 && arr[j] > last)
        {
            arr[j+1] = arr[j];
            j--;
        }
        arr[j+1] = last;
    }
     
    // Driver Method
    public static void main(String[] args)
    {
        int arr[] = {12, 11, 13, 5, 6};
      
        insertionSortRecursive(arr, arr.length);
         
        System.out.println(Arrays.toString(arr));
    }
}

Javascript

// Recursive JavaScript program for insertion sort
 
function insertionSortRecursive(arr, n) {
// Base case
if (n <= 1) {
return;
}
 
// Sort first n-1 elements
insertionSortRecursive(arr, n - 1);
 
// Insert last element at its correct position
// in sorted array.
const last = arr[n - 1];
let j = n - 2;
 
/* Move elements of arr[0..i-1], that are
greater than key, to one position ahead
of their current position */
while (j >= 0 && arr[j] > last) {
arr[j + 1] = arr[j];
j--;
}
arr[j + 1] = last;
}
 
// Driver Method
const arr = [12, 11, 13, 5, 6];
 
insertionSortRecursive(arr, arr.length);
 
console.log(arr);