Analyzing Quicksort: Average Case

• We can solve this recurrence using the dreaded substitution method

  • Guess the answer
    • T(n) = O(n lg n)
  • Assume that the inductive hypothesis holds
    • T(n) ? an lg n + b for some constants a and b
  • Substitute it in for some value < n
    • The value k in the recurrence
  • Prove that it follows for n
    • Grind through it…

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