#!/usr/bin/env ruby

require "test/unit"

# S = { a, b, c, d, e }

# { T, T, T, T, T }

# { T, T, T, T, F }

# { T, T, T, F, T }

# { T, T, T, F, F }

class Backtrack

def initialize

@org = nil

end

def identity; @org end

def subset arr; @org = arr end

def solution? curr

@org.length == curr

end

def process_solution

end

def construct_candidate

candidate = [true, false]

end

def backtrack(a, depth)

if solution? depth

process_solution

else

depth += 1

[true, false].each { |c|

a[depth] = c

backtrack(a, depth)

}

end

end

end

class TestBacktrack < Test::Unit::TestCase

def setup

@bt = Backtrack.new

end

def test_identity

@bt.subset([1])

assert_equal @bt.identity, [1]

@bt.subset([1, 2])

assert_equal @bt.identity, [1, 2]

end

end