CS 1

Lecture 9

Professor Devin Balkcom
devin@cs.dartmouth.edu
office: Sudikoff 211

http://www.cs.dartmouth.edu/~cs1

Reminders

• Exam next week, 6 - 9 pm Wednesday
• Exam review notes posted; review session Monday
• Crib sheet permitted
• Lab 1 due Monday

Tables and pairs

Sometimes, we want to write a program that works with pairs of things.

Print the whole table

1. Simplify the problem, solve. (First row?)

   for col in range(2, 5):
     print 5 * col,
   

2. Generalize the solution.

   Print an arbitrary row (in PyCharm)

3. Put the parts back together.

   Print all the rows. (in PyCharm)

Nested loops

• Good for working with pairs (e.g., tables).
• The inner loop is part of the body of the outer loop.
• Entire inner loop runs each time through outer loop.
• Step through carefully, writing down variable values.
• while or for

Nested loop example

How would you draw the blocks for Arkanoid?

Selection sort

Binary search only works on a sorted list. How can we sort a list? RTFM.