Skip to content
Related Articles

Related Articles

Save Article
Improve Article
Save Article
Like Article

Java Program for Iterative Merge Sort

  • Last Updated : 12 Jan, 2018

Following is a typical recursive implementation of Merge Sort that uses last element as pivot.

Java

Attention reader! Don’t stop learning now. Get hold of all the important DSA concepts with the DSA Self Paced Course at a student-friendly price and become industry ready.  To complete your preparation from learning a language to DS Algo and many more,  please refer Complete Interview Preparation Course.

In case you wish to attend live classes with experts, please refer DSA Live Classes for Working Professionals and Competitive Programming Live for Students.




// Recursive Java Program for merge sort
 
import java.util.Arrays;
public class GFG
{
    public static void mergeSort(int[] array)
    {
        if(array == null)
        {
            return;
        }
 
        if(array.length > 1)
        {
            int mid = array.length / 2;
 
            // Split left part
            int[] left = new int[mid];
            for(int i = 0; i < mid; i++)
            {
                left[i] = array[i];
            }
             
            // Split right part
            int[] right = new int[array.length - mid];
            for(int i = mid; i < array.length; i++)
            {
                right[i - mid] = array[i];
            }
            mergeSort(left);
            mergeSort(right);
 
            int i = 0;
            int j = 0;
            int k = 0;
 
            // Merge left and right arrays
            while(i < left.length && j < right.length)
            {
                if(left[i] < right[j])
                {
                    array[k] = left[i];
                    i++;
                }
                else
                {
                    array[k] = right[j];
                    j++;
                }
                k++;
            }
            // Collect remaining elements
            while(i < left.length)
            {
                array[k] = left[i];
                i++;
                k++;
            }
            while(j < right.length)
            {
                array[k] = right[j];
                j++;
                k++;
            }
        }
    }
    // Driver program to test above functions.
    public static void main(String[] args)
    {
        int arr[] = {12, 11, 13, 5, 6, 7};
        int i=0;
        System.out.println("Given array is");
 
        for(i=0; i<arr.length; i++)
            System.out.print(arr[i]+" ");
 
        mergeSort(arr);
 
        System.out.println("\n");
        System.out.println("Sorted array is");
 
        for(i=0; i<arr.length; i++)
            System.out.print(arr[i]+" ");
    }
}
 
// Code Contributed by Mohit Gupta_OMG

Please refer complete article on Iterative Merge Sort for more details!




My Personal Notes arrow_drop_up
Recommended Articles
Page :