aoc

Advent of Code
git clone https://git.pngu.org/aoc
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3_2021.py (1116B)

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import sys

data = sys.argv[1] if len(sys.argv) > 1 else "../day3data.txt"

N = []
for line in open(data):
    line = line.strip()
    N.append(line)
width = len(N[0])
for x in N:
    assert len(x) == width
V = [[0 for _ in range(width)] for _ in range(2)]
for x in N:
    for i, c in enumerate(x):
        V[1 if c == "1" else 0][i] += 1
gamma = ""
epsilon = ""
for i in range(width):
    if V[0][i] > V[1][i]:
        gamma += "0"
        epsilon += "1"
    else:
        gamma += "1"
        epsilon += "0"
print(int(gamma, 2) * int(epsilon, 2))

A = list(N)
B = list(N)
for i in range(width):
    if len(A) > 1:
        a0 = len([x for x in A if x[i] == "0"])
        a1 = len([x for x in A if x[i] == "1"])
        if a1 >= a0:
            A = [x for x in A if x[i] == "1"]
        else:
            A = [x for x in A if x[i] == "0"]
    if len(B) > 1:
        b0 = len([x for x in B if x[i] == "0"])
        b1 = len([x for x in B if x[i] == "1"])
        if b1 >= b0:
            B = [x for x in B if x[i] == "0"]
        else:
            B = [x for x in B if x[i] == "1"]
print(int(A[0], 2) * int(B[0], 2))