139 lines
3.7 KiB
Ruby
139 lines
3.7 KiB
Ruby
DIGIT_F = {
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" ## #" => 0,
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" ## #" => 1,
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" # ##" => 2,
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" #### #" => 3,
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" # ##" => 4,
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" ## #" => 5,
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" # ####" => 6,
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" ### ##" => 7,
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" ## ###" => 8,
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" # ##" => 9,
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}
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DIGIT_R = {
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"### # " => 0,
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"## ## " => 1,
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"## ## " => 2,
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"# # " => 3,
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"# ### " => 4,
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"# ### " => 5,
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"# # " => 6,
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"# # " => 7,
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"# # " => 8,
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"### # " => 9,
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}
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END_SENTINEL = "# #"
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MID_SENTINEL = " # # "
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def decode_upc(s)
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def decode_upc_impl(input)
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upc = input.strip
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if upc.length != 95 then
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return false
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end
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pos = 0
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digits = []
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sum = 0
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# end sentinel
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if upc[pos .. pos + 2] == END_SENTINEL then
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pos += 3
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else
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return false
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end
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# 6 left hand digits
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for i in 0 .. 5
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digit = DIGIT_F[upc[pos .. pos + 6]]
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if digit == nil then
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return false
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else
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digits.push(digit)
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sum += digit * [1, 3][digits.length % 2]
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pos += 7
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end
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end
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# mid sentinel
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if upc[pos .. pos + 4] == MID_SENTINEL then
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pos += 5
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else
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return false
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end
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# 6 right hand digits
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for i in 0 .. 5
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digit = DIGIT_R[upc[pos .. pos + 6]]
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if digit == nil then
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return false
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else
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digits.push(digit)
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sum += digit * [1, 3][digits.length % 2]
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pos += 7
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end
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end
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# end sentinel
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if upc[pos .. pos + 2] == END_SENTINEL then
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pos += 3
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else
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return false
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end
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if sum % 10 == 0 then
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print digits, " "
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return true
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else
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print "Failed Checksum "
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return false
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end
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end
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if decode_upc_impl(s) then
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puts "Rightside Up"
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elsif decode_upc_impl(s.reverse) then
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puts "Upside Down"
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else
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puts "Invalid digit(s)"
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end
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end
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def main
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num = 0
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print "%2d: " % [num += 1]
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decode_upc(" # # # ## # ## # ## ### ## ### ## #### # # # ## ## # # ## ## ### # ## ## ### # # # ")
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print "%2d: " % [num += 1]
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decode_upc(" # # # ## ## # #### # # ## # ## # ## # # # ### # ### ## ## ### # # ### ### # # # ")
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print "%2d: " % [num += 1]
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decode_upc(" # # # # # ### # # # # # # # # # # ## # ## # ## # ## # # #### ### ## # # ")
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print "%2d: " % [num += 1]
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decode_upc(" # # ## ## ## ## # # # # ### # ## ## # # # ## ## # ### ## ## # # #### ## # # # ")
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print "%2d: " % [num += 1]
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decode_upc(" # # ### ## # ## ## ### ## # ## # # ## # # ### # ## ## # # ### # ## ## # # # ")
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print "%2d: " % [num += 1]
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decode_upc(" # # # # ## ## # # # # ## ## # # # # # #### # ## # #### #### # # ## # #### # # ")
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print "%2d: " % [num += 1]
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decode_upc(" # # # ## ## # # ## ## # ### ## ## # # # # # # # # ### # # ### # # # # # ")
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print "%2d: " % [num += 1]
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decode_upc(" # # # # ## ## # # ## ## ### # # # # # ### ## ## ### ## ### ### ## # ## ### ## # # ")
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print "%2d: " % [num += 1]
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decode_upc(" # # ### ## ## # # #### # ## # #### # #### # # # # # ### # # ### # # # ### # # # ")
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print "%2d: " % [num += 1]
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decode_upc(" # # # #### ## # #### # # ## ## ### #### # # # # ### # ### ### # # ### # # # ### # # ")
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end
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main()
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