45 lines
741 B
Crystal
45 lines
741 B
Crystal
require "advent"
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INPUT = input(2020, 8).lines.map do |s|
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code, int = s.split(" ")
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{code, int.to_i32}
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end
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def run(prog)
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acc = 0
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pc = 0
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visited = Set(Int32).new
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loop do
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return {:term, acc} if pc >= prog.size
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return {:inf, acc} if visited.includes? pc
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visited << pc
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code, int = prog[pc]
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case code
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when "acc"
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acc += int
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when "jmp"
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pc += int - 1
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end
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pc += 1
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end
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end
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def part1
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run(INPUT)[1]
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end
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def part2
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jnp = INPUT.find_indices { |e| e[0] == "jmp" || e[0] == "nop" }
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jnp.each do |i|
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prog = INPUT.clone
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op, int = prog[i]
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prog[i] = {op.tr("jmpnop", "nopjmp"), int}
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code, acc = run(prog)
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return acc if code == :term
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end
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end
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puts part1
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puts part2
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