CS21: Quiz 5 Study Guide

In addition to the concepts below, you should also know the concepts from Quiz 1, Quiz 2, Quiz 3, and Quiz 4.

You should understand the following terms:

Practice problems:

  1. True/False questions:
    • Linear search requires a number of steps proportional to the size of the list being searched (T/F)
    • The python in operator performs a binary search (T/F)
    • Binary search is an NlogN algorithm (T/F)
    • The number of times N can be divided by 2 is log base-two of N (T/F)
  2. Approximately how many iterations will binary search need to find a value in a list of 1 million items?
  3. Place these algorithm classes in order from best to worst: N, logN, N*N, NlogN
  4. What is log(1024,2) in python? What about log(2048,2)?
  5. How many steps are required for each of the following: N, logN, N*N, NlogN?
    #############################################
    for i in range(n):
      for j in range(n):
        print i, j
    #############################################
    while n > 1:
      print n
      n = n/2
    #############################################
    for i in range(n):
      for j in range(10):
        print i, j
    #############################################
    
  6. Show the index values for low, high, and mid for each step in searching the list L for the value x using binary search.
    x = 99
    L = [-20, -12, -4, 1, 7, 44, 45, 46, 58, 67, 99, 145]     low   mid   high
           0    1   2  3  4   5   6   7   8   9  10   11      ----------------
    
    
    
    
    
    
    
    
    

  7. Given the following assignments:
       ls = ["fish", "squirrel", "cat", "dog", "monkey", "pony"]
       s = "a,b,c,d,e"
    
    What are the value and type of the following expressions:
      (1) ls[3]
      (2) ls[3] > "apple" 
      (3) ls[3][1]
      (4) 'b' < 'f'
      (5) len(ls[5])
      (6) range(len(ls))
      (7) range(len(ls[0]))
      (8) s.split(",")