mergesort.java

import java.util.Arrays;

public class mergesort {
    public static int[] merge(int[] array1,int[] array2){
        int[] combined=new int[array1.length+array2.length];
        int index=0;
        int i=0;
        int j=0;
        while(i<array1.length && j<array2.length){
            if(array1[i]<array2[j])
            combined[index++]=array1[i++];
            else
            combined[index++]=array2[j++];
        }
        while(i<array1.length)
        combined[index++]=array1[i++];
        while(j<array2.length)
        combined[index++]=array2[j++];
        return combined;
    }
    public static int[] mergeSort(int[] array){
        if(array.length==1)
        return array;
        int midIndex=array.length/2;
        int[] left=mergeSort(Arrays.copyOfRange(array,0, midIndex));
        int[] right=mergeSort(Arrays.copyOfRange(array, midIndex, array.length));
        return merge(left,right);
    } 
    public static void main(String args[]){
        int[] originalArray={4,6,2,1};
        int[] sortedArray=mergeSort(originalArray);
        System.out.println("Original Array: "+Arrays.toString(originalArray));
        System.out.println("Sorted Array: "+Arrays.toString(sortedArray));

    }
    
}