Sorting Algorithms - 3 merge Sort

import java.util.Arrays;public class Main {    public static void main(String[] args) {      int[] arr = new int[]{5,9,2,7,1,10,4,1,50};      System.out.println("unsorted Array : "+Arrays.toString(arr));      margeSort(arr,0,arr.length-1);       System.out.println("sorted Array in ascending order : "+Arrays.toString(arr));    }   private static void margeSort(int[] arr,int left,int right){    // return if arr size becomes 1    if(left >= right) return;    // calculate the mid    int mid = ( left + right ) / 2;    // divide the array into two subarrays    margeSort(arr,left,mid);    margeSort(arr,mid+1,right);    // merge subarrays    merge(arr,left,mid,right);   }   private static void merge(int[] arr,int left,int mid,int right){    // calculate the size of left & right subarrays    int leftArrSize = mid - left+1;    int rightArrSize = right - mid;    // initialise temp subarrays    int[] leftArr = new int[leftArrSize];    int[] rightArr = new int[rightArrSize];    // copy left & right array into temp arrays    for (int i = 0; i < leftArrSize; ++i)      leftArr[i] = arr[left + i];    for (int j = 0; j < rightArrSize; ++j)    rightArr[j] = arr[mid + 1 + j];    // set initial indexes of subarrays    int leftPointer = 0;    int rightPointer = 0;    int arrPointer = left;    // copy temp subarrays, in ascending order    while(leftPointer < leftArrSize && rightPointer < rightArrSize ){      if(leftArr[leftPointer] <= rightArr[rightPointer]){        arr[arrPointer] = leftArr[leftPointer];        arrPointer++;        leftPointer++;      }else{        arr[arrPointer] = rightArr[rightPointer];        arrPointer++;        rightPointer++;      }    }    // copy the remaining elements of left subarray into a marge array    while(leftPointer < leftArrSize){      arr[arrPointer] = leftArr[leftPointer];      arrPointer++;      leftPointer++;    }    // copy the remaining elements of right subarray into a merge array    while(rightPointer < rightArrSize){      arr[arrPointer] = rightArr[rightPointer];      arrPointer++;      rightPointer++;    }   }}