Here are the solutions to problems 1 and 2. I'll be posting 3/4 as soon as I have it annotated.
PS 2: Problem 1
# Initialize configuration variables
coefficients = 6, 9, 20
mcnuggets = range( 50, 56 )
terms = len(coefficients)
combos = [] # Holds list of combinations.
a = 0 # coefficient: 6
b = 0 # coefficient: 9
c = 0 # coefficient: 20
# Loop through the mcnuggets range.
for n in mcnuggets:
ranges = [] # Holds test ranges.
# Create test ranges for the coefficients for this value of n.
for i in range(0, terms):
limit = int( n / coefficients[i] ) + 1
i_range = range( 0, limit )
ranges.append(i_range)
n_combos = [] # Holds all combos for a given n
# Loop through the test range.
for a in ranges[0]:
for b in ranges[1]:
for c in ranges[2]:
# Check to see if the sum of the terms is equal to n.
if (a*coefficients[0]) + (b*coefficients[1]) + (c*coefficients[2]) == n:
# If so, create an array of this combination.
combo = [ a, b, c ]
# Append it to the collection of combos for this n.
n_combos.append(combo)
#Print combos for this n.
print 'For n = ', n
print 'Combos:', n_combos
PS 2: Problem 2
Theorem:If it is possible to buy x, x+1,…, x+5 sets of McNuggets, for some x, then it is possible to buy any number of McNuggets >= x, given that McNuggets come in 6, 9 and 20 packs.
Explain, in English, why this theorem is true.
The key is in the given: The smallest coefficient is 6. Once you find solutions for six consecutive amounts, every amount beyond the last one can be derived by adding 6-packs to one of the consecutive solutions.
In the abstract, the minimum number of consecutive solutions required to insure that every subsequent number has a solution is equal to the smallest coefficient of the terms.