Java Program for Recursive Insertion Sort
Last Updated :
14 Mar, 2023
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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]
// 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));
}
}
// 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);
Output:-
[5, 6, 11, 12, 13]
Time Complexity: O(n2)
Auxiliary Space: O(1)
Please refer complete article on Recursive Insertion Sort for more details!
