Sha256: a94f5caef12805da1ca004826b1811932608947d2ec5000c043e934fb0edd87d
Contents?: true
Size: 1.2 KB
Versions: 11
Compression:
Stored size: 1.2 KB
Contents
pad = (n, len) ->
len ?= 3
res = n.toString()
res = ' '+res while res.length < len
res
shifts = [[-2, +1], [-1, +2], [+1, +2], [+2, +1], [+2, -1], [+1, -2], [-1, -2], [-2, -1]]
class Solver
constructor: (@n) ->
@nn = @n * @n
@n2 = @n + @n
@desk = []
@depth = 0
for r in [0...@n]
@desk.push (0 for col in [0...@n])
@solve 0, 0
solve: (r, c) ->
@desk[r][c] = ++@depth
return true if @depth >= @nn
for [r1, c1] in @moves(r, c)
return true if @solve(r1, c1)
@desk[r][c] = 0
@depth--
false
# Coffeescript does not support generators
moves: (r, c) ->
res = []
for [sr, sc] in shifts
r1 = r + sr
if 0 <= r1 < @n
c1 = c + sc
if 0 <= c1 < @n && @desk[r1][c1]==0
res.push [r1, c1]
res
toString: ->
res = []
for r in [0...@n]
res.push ( (if x==0 then ' .' else pad(x,3)) for x in @desk[r]).join('')
res.join "\n"
timing = (name, cb) ->
start = new Date().getTime()
res = cb()
console.log("#{name}: #{(new Date().getTime() - start)/1000}")
res
#result = timing 'KN h8', ->
# new Solver(7, 3).toString()
#console.log result
return (n, left) ->
new Solver(n, left).toString()
Version data entries
11 entries across 11 versions & 1 rubygems