cryptarithms or alphametics

HAWAII + IDAHO + IOWA + OHIO == STATES

Python program originally written by Raymond Hettinger. This program solves alphametic puzzles in just 14 lines of code.

import re
import itertools

def solve(puzzle):
words = re.findall(‘[A-Z]+’, puzzle.upper())
unique_characters = set(”.join(words))
assert len(unique_characters) <= 10, 'Too many letters'
first_letters = {word[0] for word in words}
n = len(first_letters)
sorted_characters = ''.join(first_letters) + \
''.join(unique_characters – first_letters)
characters = tuple(ord(c) for c in sorted_characters)
digits = tuple(ord(c) for c in '0123456789')
zero = digits[0]
for guess in itertools.permutations(digits, len(characters)):
if zero not in guess[:n]:
equation = puzzle.translate(dict(zip(characters, guess)))
if eval(equation):
return equation

if __name__ == '__main__':
import sys
for puzzle in sys.argv[1:]:
print(puzzle)
solution = solve(puzzle)
if solution:
print(solution)
# Ported to Python 3 and modified by Mark Pilgrim
# original: http://code.activestate.com/recipes/576615/
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