My Advent of Code solutions in Python.
kevinyap.ca/2019/12/going-fast-in-advent-of-code/
advent-of-code
python
Add 2025/06
+58
+58
2025/day06.py
+58
2025/day06.py
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import fileinput
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import math
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import re
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GROUP_RE = r'[\d*+]+'
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# Parse problem input.
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MATRIX = []
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ALL_NUMS = []
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for y, line in enumerate(fileinput.input()):
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# Parse whole groups for part 1.
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groups = re.findall(GROUP_RE, line)
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if '*' not in groups:
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ALL_NUMS.append(groups)
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else:
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OPS = groups
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# Add a "simulated" blank line before the list of
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# operations to make part 2 processing easier.
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MATRIX.append([' ' for _ in range(len(MATRIX[-1]))])
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# Create a matrix to transpose for part 2.
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MATRIX.append(list(line))
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# Solve part 1.
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OPERANDS = list(zip(*ALL_NUMS))
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PART_1 = 0
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for operands, op in zip(OPERANDS, OPS):
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operands = [int(n) for n in operands]
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if op == '+':
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PART_1 += sum(operands)
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else:
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PART_1 += math.prod(operands)
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print("Part 1:", PART_1)
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# Solve part 2.
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FLIPPED = list(zip(*MATRIX))
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TAPE = ''.join(''.join(col) for col in reversed(FLIPPED))
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PART_2 = 0
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buffer = []
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for group in re.findall(GROUP_RE, TAPE):
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if group == '+':
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PART_2 += sum(buffer)
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buffer = []
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elif group == '*':
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PART_2 += math.prod(buffer)
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buffer = []
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else:
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buffer.append(int(group))
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print("Part 2:", PART_2)
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