quicksort

public void quicksort(int[] array, int low, int high){
        int i = low;
        int j = high;
        if(i>j)
            return;
        int pivot = i + (j-i)/2;
        int pnum = array[pivot];
        while(i<=j){
            // array[i] == pnum error. because have to be swap.
            while(i<=j && array[i]<pnum)
                i++;
            while(i<=j && array[j]>pnum)
                j--;
            if(i<=j){
            exchange(array,i,j);
            i++;
            j--;
            }
        }
          // Recursion
          quicksort(array,low, j);
          quicksort(array,i, high);
        
        
    }