TIL about maketrans and also corrected some 6am mistakes

05/05_refactored.py

@@ -0,0 +1,31 @@
+def read_file():
+	with open("input.txt","r") as f:
+		return f.read().split('\n')
+
+def id(seat):
+	"""
+	Translate to binary.
+	"""
+	return int(seat.translate(str.maketrans('FBLR', '0101')), 2)
+
+def part1(seats):
+	"""
+	Find the highest seat ID.
+	"""
+	ids = sorted(map(id, seats))
+	return max(ids)
+
+def part2(seats):
+	"""
+	Find your seat ID, which is missing.
+	"""
+	ids = sorted(map(id, seats))
+	return sum( range(min(ids), max(ids)+1) ) - sum(ids)
+
+def main():
+	seats = read_file()
+	print(f'{part1(seats)=}')
+	print(f'{part2(seats)=}')
+
+if __name__ == "__main__":
+	main()

05/05_translate.py

@@ -0,0 +1,25 @@
+"""
+Turns out int() accepts different bases than 10.
+We can also translate a string using translate() and a table,
+	or maketrans(). #TIL
+"""
+
+with open("input.txt", "r") as f:
+	seats = f.read().split('\n')
+
+def id(code):
+	trans = str.maketrans('FBLR', '0101')
+	return int(code.translate(trans), 2) # it's literally just binary lmao -- x8 just means x1000 so shift 3 places, and there are 3 digits in the colpart
+
+ids = [id(seat) for seat in seats]
+print(f"Part 1: {max(ids)}") # i forgot that max() existed whoops
+
+"""
+Also, instead of iterating over the entire list of IDs,
+	we can find the missing seat by simply summing them.
+The missing seat will be excluded from the total.
+"""
+
+expected_total = sum( range(min(ids), max(ids)+1) ) # some seats are missing
+actual_total = sum(ids)
+print(f"Part 2: {expected_total - actual_total}")