title: Probabilty based on quicksort partition
body: <p>I have come across this question: </p>
  
  <p>Let 0&lt;α&lt;.5 be some constant (independent of the input array length n). Recall the Partition subroutine employed by the QuickSort algorithm, as explained in lecture. What is the probability that, with a randomly chosen pivot element, the Partition subroutine produces a split in which the size of the smaller of the two subarrays is ≥α times the size of the original array?</p>
  
  <pre><code>Its answer is 1-2*α.
  </code></pre>
  
  <p>Can anyone explain me how has this answer come?Please Help.</p>