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using DelimitedFiles
infile = size(ARGS, 1) > 0 ? ARGS[1] : "day3input.txt"
println("infile = ", infile)
diags = readdlm(infile, ' ', String)
n = size(diags, 1)
w = length(diags[1])
half_n = n / 2
gamma = 0
epsilon = 0
for i in 1:w
global gamma, epsilon
is_one_at_i(s) = s[i] == '1' ? true : false
one_count = size(findall(is_one_at_i, diags), 1)
v = 2^(w-i)
if one_count > half_n
gamma += v
else
epsilon += v
end
end
println("gamma = ", gamma)
println("epsilon = ", epsilon)
println("prod = ", gamma * epsilon)
o2gen = view(diags, :)
co2scrub = view(diags, :)
o2n = n
co2n = n
for i in 1:w
global o2gen, co2scrub, o2n, co2n
is_one_at_i(s) = s[i] == '1' ? true : false
is_zero_at_i(s) = s[i] == '0' ? true : false
o2idx_ones = findall(is_one_at_i, o2gen)
co2idx_ones = findall(is_one_at_i, co2scrub)
if length(o2gen) > 1
if length(o2idx_ones) >= o2n/2
o2gen = o2gen[o2idx_ones]
else
o2gen = o2gen[findall(is_zero_at_i, o2gen)]
end
o2n = length(o2gen)
end
if length(co2scrub) > 1
if length(co2idx_ones) < co2n/2
co2scrub = co2scrub[co2idx_ones]
else
co2scrub = co2scrub[findall(is_zero_at_i, co2scrub)]
end
co2n = length(co2scrub)
end
end
o2gen_v = parse(Int, o2gen[1], base=2)
co2scrub_v = parse(Int, co2scrub[1], base=2)
println("o2gen ", o2gen, " ", o2gen_v)
println("co2scrub ", co2scrub, " ", co2scrub_v)
println("prod ", o2gen_v * co2scrub_v)