Java Program for Iterative Merge Sort

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

Java

// 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!

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.

My Personal Notes

Java

Recommended Posts: