counting quicksort comparisions

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Java

hey
i am still a beginner at programming but i am trying to write a program that counts the number of comparisons in a quicksort program


this is my code

package algo_quicksort;

public class Algo_quicksort {

    public static int partition(int[]A,int p,int r){
        int x=A[p];
        int i=p+1;
        int temp;
        for(int j=p+1;j<r;j++){
            if(A[j]<x){//if A[j] is bigger than the pivot do nothing 
                temp=A[j];
                A[j]=A[i];
                A[i]=temp;
                i++;
            }
        }
        temp=A[p];
        A[p]=A[i-1];
        A[i-1]=temp;
        return i-1;
    }
    public static long quickSort(int[]A,int startPos,int length){
        if(length==1){
            return 0;
        }
        else{
            if(startPos<length){
            int pivot= partition(A,0,length);
          quickSort(A,startPos,pivot+1);
          quickSort(A, pivot+2,length); 
            return length-startPos-1;
        }
            else{
                return 0;
            }
    }
    }
    
    
    public static void main(String[] args) {
        int a[]={3,2,4};
        System.out.println("# of comparisons is: " +quickSort(a,0,a.length));

        System.out.println("A[] after quicksort is: ");
        
        for(int i=0;i<a.length;i++){
            System.out.print(a[i]+"  ");
        }

    }
}

it works perfectly for any array of size 3 or less
but if it is any bigger than that it gives me a stackoverflow exception at the recursive call
i tried debugging my code but could not figure out where it's going wrong
i would appreciate any help i get ^_^