61 lines
1.5 KiB
Crystal
61 lines
1.5 KiB
Crystal
require "advent"
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raw = input(2020, 14).lines
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input = [] of {UInt64, UInt64, Array(Int32), UInt64, UInt64}
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and_mask = (2_u64**63) + (2_u64**63-1)
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or_mask = 0_u64
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floats = [] of Int32
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raw.each do |line|
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if data = line.match(/^mask = (.+)$/)
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new_mask = data[1]
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and_mask = (2_u64**63) + (2_u64**63-1)
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or_mask = 0_u64
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floats = [] of Int32
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new_mask.reverse.chars.each_with_index do |c, i|
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floats << i if c == 'X'
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or_mask = or_mask | (1_u64 << i) if c == '1'
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and_mask = and_mask & ~(1_u64 << i) if c == '0'
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end
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elsif data = line.match(/^mem\[(\d+)\] = (\d+)$/)
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input << {and_mask, or_mask, floats, data[1].to_u64, data[2].to_u64}
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else
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raise "Invalid line"
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end
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end
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def part1(input)
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memory = {} of UInt64 => UInt64
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input.each do |i|
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and_mask, or_mask, floats, addr, v = i
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memory[addr] = (v & and_mask) | or_mask
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end
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memory.values.sum
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end
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def generate_possible(indices, index, n, &block : UInt64 -> _)
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if index == indices.size
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yield n
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return
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end
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float_addr = indices[index]
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no = n | (1_u64 << float_addr)
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generate_possible(indices, index+1, no, &block)
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nz = n & ~(1_u64 << float_addr)
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generate_possible(indices, index+1, nz, &block)
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end
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def part2(input)
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memory = {} of UInt64 => UInt64
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input.each do |i|
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_, or_mask, floats, addr, v = i
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generate_possible(floats, 0, addr | or_mask) do |addr|
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memory[addr] = v
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end
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end
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memory.values.sum
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end
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puts part1(input)
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puts part2(input)
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