Created
August 2, 2019 13:10
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Solves a problem about guessing numbers from sums and products
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products = dict() | |
for i in range(2, 101): | |
for j in range(i, 101): | |
products[i * j] = products.get(i * j, []) + [(i, j)] | |
ambiguous_products = set() | |
for product in products: | |
if len(products[product]) > 1: | |
ambiguous_products.add(product) | |
possible_sums = [] | |
for s in range(4, 201): | |
all_ambiguous = True | |
for i in range(2, s // 2 + 1): | |
j = s - i | |
product = i * j | |
if product not in ambiguous_products: | |
all_ambiguous = False | |
break | |
if all_ambiguous: | |
possible_sums.append(s) | |
new_products = dict() | |
for s in possible_sums: | |
for i in range(2, s // 2 + 1): | |
j = s - i | |
new_products[i * j] = new_products.get(i * j, []) + [(i, j)] | |
unique_products = set() | |
for product in new_products: | |
if len(new_products[product]) == 1: | |
unique_products.add(product) | |
sums = dict() | |
for product in unique_products: | |
for i, j in new_products[product]: | |
sums[i + j] = sums.get(i + j, []) + [(i, j)] | |
unique_sums = [] | |
for s in sums: | |
if len(sums[s]) == 1: | |
unique_sums.append(s) | |
assert(len(unique_sums) == 1) | |
real_sum = unique_sums[0] | |
candidates = [] | |
for i in range(2, real_sum // 2 + 1): | |
j = real_sum - i | |
if i * j in unique_products: | |
candidates.append((i, j)) | |
assert(len(candidates) == 1) | |
print(candidates[0]) |
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