E X E R C I S E # 3 7 : C H A N G E M A K E R makeChange(30)
→
{'quarters': 1, 'nickels': 1}
American currency has coins in the denominations of 1 (pennies), 5 (nickels), 10 (dimes), and 25
cents (quarters). Imagine that we were programming a cash register to dispense correct change. In this
exercise, we would need to calculate the number of each coin for a given amount of change.
Exercise Description Write a makeChange() function with an amount parameter. The amount parameter contains
an integer of the number of cents to make change for. For example, 30 would represent 30 cents and
125
would represent $1.25. This function should return a dictionary with keys 'quarters',
'dimes'
, 'nickels', and 'pennies', where the value for a key is an integer of the number of
this type of coin.
The value for a coin’s key should never be 0. Instead, the key should not be present in the
dictionary. For example, makeChange(5) should return {'nickels': 1} and not
{'quarters’: 0, 'dimes': 0, 'nickels': 1, 'pennies': 0}
.
For example, makeChange(30) would returns the dictionary {'quarters': 1,
'nickels': 5}
to represent the coins used for 30 cents change. The function should use the
minimal number of coins. For example, makeChange(10) should return {'dimes': 1} and not
{'nickels': 2}
, even though they both add up to 10 cents.
These Python assert statements stop the program if their condition is False. Copy them to
the bottom of your solution program. Your solution is correct if the following assert statements’
conditions are all True:
assert makeChange(30) == {'quarters': 1, 'nickels': 1}
assert makeChange(10) == {'dimes': 1}
assert makeChange(57) == {'quarters': 2, 'nickels': 1, 'pennies': 2}
assert makeChange(100) == {'quarters': 4}
assert makeChange(125) == {'quarters': 5}
Try to write a solution based on the information in this description. If you still have trouble
solving this exercise, read the Solution Design and Special Cases and Gotchas sections for
additional hints.
Prerequisite concepts: modulo operator, integer division
