Stackoverflow with Quicksort Java implementation

Question

Having some problems implementing quicksort in java. I get a stackoverflow error when I run this program and I\'m not exactly sure why. If anyone can point out the error, it

Answer 1

You can try this:

public void sort(int[] A) {
        if (A == null || A.length == 0)
            return;
        quicksort(A, 0, A.length - 1);
    }

    public void quicksort(int[] A, int left, int right) {
        int pivot = A[left + (right - left) / 2];
        int i = left;
        int j = right;
        while (i <= j) {
            while (A[i] < pivot) {
                i++;
            }
            while (A[j] > pivot) {
                j--;
            }
            if (i <= j) {
                exchange(i, j);
                i++;
                j--;
            }
        }

        if(left < j)
            quicksort(A,left,j);
        if(i < right)
            quicksort(A,i,right);
    }

    public void exchange(int i, int j){
        int temp=A[i];
        A[i]=A[j];
        A[j]=temp;
    }

    public String toString() {
        String s = "";
        s += "[" + A[0];
        for (int i = 1; i < A.length; i++) {
            s += ", " + A[i];
        }
        s += "]";
        return s;
    }

Source: Code 2 Learn: Quick Sort Algorithm Tutorial