"n">ListNode</span><span class="o">*</span></code> by reference. Explain why the pointer itself needs to be passed by reference and what the consequence would be if it were not.</p>
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<h3 id="quicksort">QuickSort</h3>
<p>QuickSort is an example of a recursive "divide-and-conquer" algorithm. It divides the input list into sublists, recursively sorts the sublists, and then joins the sorted sublists into one combined whole.  QuickSort is known as a "hard-divide, easy-join" algorithm because the bulk of i