CSC111 Homework 12 2015

--D. Thiebaut (talk) 17:30, 19 April 2015 (EDT)

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Problem #2

Write a program called hw12_1.py that contains a recursive function called minmax() which returns the smallest and largest elements of a list of items. The items may be strings, numbers, or tuples, where the first element of the tuple is either a number or a string.

Example main() program:

def main():
     A = [ 1, 10, 20, 3, 2, -1, -10, 5, 5, 5, 5 ]
     low, high = minmax( A )
     print( "smallest item =", low, " largest item = ", high )
     # will print
     # smallest item = -10 largest item = 20

     A = [ 1 ]
     low, high = minmax( A )
     print( "smallest item =", low, " largest item = ", high )
     # will print
     # smallest item = 1 largest item = 1
 
     A = [ ]
     low, high = minmax( A )
     print( "smallest item =", low, " largest item = ", high )
     # will print
     # smallest item = None largest item = None

     A = [ "alpha", "beta", "gamma", "epsilon" ]
     low, high = minmax( A )
     print( "smallest item =", low, " largest item = ", high )
     # will print
     # smallest item = alpha largest item = gamma

if __name__=="__main__":
     main()

Requirements

1. The function minmax() must be recursive.
2. You cannot use the min() or max() standard Python functions. If you want to find the largest of two items, you need to do the comparison in Python, using <, <=, >, or >=.

Submission

Submit your program to the Moodle section, HW12 PB 1