Class 28 — Wednesday March 27

Tasty problem solving

Winning strategy — Mindful collaboration — Doing it today

---

Look both ways

• Back or ahead

---

Agenda

• Being functional

• Working with others

---

You got to see it, to believe it

• Pair programming

---

Example de jeur — module beanery

• Module beanery defines three functions volume(), count(), and guess().

• A simple tester yum.py is provided.

---

Function volume( a, b )

• Returns the volume of jelly bean with length a and height b. Based upon hours of research, zillions of jelly beans, and a bunch of mason jars, it has been concluded that the volume of a jelly bean can be roughly modeled as the average of the volume of the exterior bounding cylinder and of the volume of the interior bounding ellipsoid. Our formula for the volume s of a single jelly bean is:

To make your calculation as accurate as possible, use Python's estimate of π when needed.

• A run of of the tester should produce output

volume( 1.3 , 0.7 ): 0.41691552507014545

volume( 2.0 , 1.0 ): 1.3089969389957472

---

Function count( s, j, f )

• Returns the number of beans of volume s that can fit a jar with volume j given the loading capacity is f.

• The count formula for the volume j of a single jelly bean is:

⌊ j f / s ⌋ ;

where the ⌊ ⌋ operators are the mathematical symbols for rounding down to the nearest integer.

• A run of of the tester should produce output

count( 0.42 , 125 , 0.7 ): 208

count( 1.31 , 500 , 0.6 ): 229

---

Function guess( a, b, j )

• Returns the number of number jelly beans with length a and height b that can fit in a jar with volume j. Exhaustive research has determined the jelly bear jar loading factor is typically 69.8% (i.e., .698).

• A run of of the tester should produce output

guess( 1.3 , 0.7 , 125 ): 209

guess( 2.0 , 1.0 , 500 ): 266

guess( 1.52 , 0.9 , 1550 ): 1342

---

To do

• CodingBat

• Review recent epistles and slide decks