Merge Sort

class Solution
{
   
    void merge(int arr[], int l, int mid, int r)
    {
         // Your code here
        int n1 = mid-l+1;
        int n2 = r-mid;
       
        int[] left = new int[n1];
        int[] right = new int[n2];
       
        int i, j, k;
       
        for(i = 0; i < n1; i++) 
        left[i] = arr[l+i];
        
        for(j = 0; j < n2; j++)
        right[j] = arr[mid+1+j];
       
        i = 0;
        j = 0;
        k = l;
       
        while(i < n1 && j < n2)
        {
            if(left[i] < right[j])
                arr[k++] = left[i++];
           
            else
                arr[k++] = right[j++];
        }
       
        while(i < n1)
            arr[k++] = left[i++];
       
        while (j < n2)
            arr[k++] = right[j++];
         
    }
    
    
    void mergeSort(int arr[], int l, int r)
    {
        //code here
        if(l >= r) return;
        int mid = (l+r)/2;
        mergeSort(arr, l, mid);
        mergeSort(arr, mid+1, r);
        merge(arr, l, mid, r);
        

    }
}