84 lines
3.5 KiB
Text
84 lines
3.5 KiB
Text
local fmt = require "fmt"
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require "perm"
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local colors = {"Red", "Green", "White", "Yellow", "Blue"}
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local nations = {"English", "Swede", "Danish", "Norwegian", "German"}
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local animals = {"Dog", "Birds", "Cats", "Horse", "Zebra"}
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local drinks = {"Tea", "Coffee", "Milk", "Beer", "Water"}
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local smokes = {"Pall Mall", "Dunhill", "Blend", "Blue Master", "Prince"}
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local p = perm.list({1, 2, 3, 4, 5})
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local function check(a1, a2, v1, v2)
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for i = 1, 5 do
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if p[a1][i] == v1 then return p[a2][i] == v2 end
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end
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return false
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end
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local function check_left(a1, a2, v1, v2)
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for i = 1, 4 do
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if p[a1][i] == v1 then return p[a2][i + 1] == v2 end
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end
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return false
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end
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local function check_right(a1, a2, v1, v2)
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for i = 2, 5 do
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if p[a1][i] == v1 then return p[a2][i - 1] == v2 end
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end
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return false
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end
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local function check_adjacent(a1, a2, v1, v2)
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return check_left(a1, a2, v1, v2) or check_right(a1, a2, v1, v2)
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end
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local function print_houses(c, n, a, d, s)
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local owner = ""
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print("House Color Nation Animal Drink Smokes")
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print("===== ====== ========= ====== ====== ===========")
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for i = 1, 5 do
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local f = "%3d %-6s %-9s %-6s %-6s %-11s"
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local l = {i, colors[p[c][i]], nations[p[n][i]], animals[p[a][i]], drinks[p[d][i]], smokes[p[s][i]]}
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fmt.print(f, l:unpack())
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if animals[p[a][i]] == "Zebra" then owner = nations[p[n][i]] end
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end
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print($"\nThe {owner} owns the Zebra\n")
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end
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local function fill_houses()
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local solutions = 0
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for c = 1, 120 do
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if !check_left(c, c, 2, 3) then continue end -- C5 : Green left of white
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for n = 1, 120 do
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if p[n][1] != 4 then continue end -- C10: Norwegian in First
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if !check(n, c, 1, 1) then continue end -- C2 : English in Red
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if !check_adjacent(n, c, 4, 5) then continue end -- C15: Norwegian next to Blue
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for a = 1, 120 do
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if !check(a, n, 1, 2) then continue end -- C3 : Swede has Dog
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for d = 1, 120 do
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if p[d][3] != 3 then continue end -- C9 : Middle drinks Milk
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if !check(d, n, 1, 3) then continue end -- C4 : Dane drinks Tea
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if !check(d, c, 2, 2) then continue end -- C6 : Green drinks Coffee
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for s = 1, 120 do
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if !check(s, a, 1, 2) then continue end -- C7 : Pall Mall has Birds
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if !check(s, c, 2, 4) then continue end -- C8 : Yellow smokes Dunhill
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if !check(s, d, 4, 4) then continue end -- C13: Blue Master drinks Beer
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if !check(s, n, 5, 5) then continue end -- C14: German smokes Prince
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if !check_adjacent(s, a, 3, 3) then continue end -- C11: Blend next to Cats
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if !check_adjacent(s, a, 2, 4) then continue end -- C12: Dunhill next to Horse
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if !check_adjacent(s, d, 3, 5) then continue end -- C16: Blend next to Water
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++solutions
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print_houses(c, n, a, d, s)
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end
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end
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end
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end
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end
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return solutions
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end
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local solutions = fill_houses()
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local plural = fmt.plural(solutions, "solution")
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print($"{solutions} {plural} found")
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