Computer Science 3650
Summer 2000
Exercise 2

Assigned: June 28
Due: June 30.

  1. (page 64, 4-3-1) Use the master method to give tight asymptotic bounds for each of the following recurrences.

    1. T(n) = 4T(n/2) + n
    2. T(n) = 4T(n/2) + n2
    3. T(n) = 4T(n/2) + n3

  2. (page 64, 4-3-2) The running time of algorithm A is described by the recurrence T(n) = 7T(n/2) + n2. A competing algorithm A' has a running time of T'(n) = aT(n/4) + n2. What is the largest integer value for a such that A' is asymptotically faster than A?

  3. (page 72, 4-1 a-c) Give asymptotic upper and lower bounds for T(n) in each of the following recurrences. Assume that T(n) is constant for n <= 2. Make your bounds as tight as possible, and justify your answers.

    1. T(n) = 2T(n/2) + n3
    2. T(n) = T(9n/10) + n
    3. T(n) = 16T(n/4) + n2