matrix_mult_concat.rb

# https://twitter.com/potetoichiro/status/1538130783785095173 を見て遊んでみた

hoge=(11..99).select{_1%10!=0}.to_h do |num|
  a, b = num.divmod 10  
  nums = (1..9).to_a
  combinations = nums.repeated_permutation(4).select do |a2, a3, b2, b3|
    num == a * b + a2 * b2 + a3 * b3
  end
  [num, combinations.map{|a2,a3,b2,b3|[[a,a2,a3],[b,b2,b3]]}]
end

nums=(1..9).to_a
ltors = 3.times.map{|i|
  3.times.map{|j|
    nums.repeated_permutation(3).to_h do |l|
      [l,
        nums.repeated_permutation(3).select{|r|
          l[0]*r[0]+l[1]*r[1]+l[2]*r[2]==l[i]*10+r[j]
        }
      ]
    end
  }
};1

cnt=0
l1l2s = []
max=[*1..9].repeated_permutation(6).size
[*1..9].repeated_permutation(6).each do |nums|
  cnt+=1
  l1, l2, l3 = nums.each_slice(3).to_a
  as=ltors[0][0][l1]&ltors[0][1][l2]
  bs=ltors[1][0][l1]&ltors[1][1][l2]
  cs=ltors[2][0][l1]&ltors[2][1][l2]
  puts "#{cnt}/#{max}" if cnt%10000==0
  if as&&bs&&cs&&as.size>0&&bs.size>0&&cs.size>0
    l1l2s<<[l1,l2]
  end
end


max=l1l2s.size
answers_left = {};cnt=0;l1l2s.each do |(l1,l2)|
  cnt+=1
  as=ltors[0][0][l1]&ltors[0][1][l2]
  bs=ltors[1][0][l1]&ltors[1][1][l2]
  cs=ltors[2][0][l1]&ltors[2][1][l2]
  l3a = ltors[0][2].reject{(_2 & as).empty?}.keys
  next if l3a.empty?
  l3b = ltors[1][2].reject{(_2 & bs).empty?}.keys
  next if l3b.empty?
  l3c = ltors[2][2].reject{(_2 & cs).empty?}.keys
  next if l3c.empty?
  puts "#{cnt}/#{max}" if cnt%100==0
  (l3a&l3b&l3c).each do |l3|
    as_=as&ltors[0][2][l3]
    bs_=bs&ltors[1][2][l3]
    cs_=cs&ltors[2][2][l3]
    if as_&&bs_&&cs_&&as_.size>0&&bs_.size>0&&cs_.size>0
      answers_left[l1+l2+l3]=true
    end
  end
end
answers_left = answers_left.keys

puts "combinations: #{answers_left.size}"

answers_left.each do |nums|
  l1, l2, l3 = nums.each_slice(3).to_a
  r1=(ltors[0][0][l1]&ltors[0][1][l2]&ltors[0][2][l3]).first
  r2=(ltors[1][0][l1]&ltors[1][1][l2]&ltors[1][2][l3]).first
  r3=(ltors[2][0][l1]&ltors[2][1][l2]&ltors[2][2][l3]).first
  p [l1,l2,l3,r1,r2,r3] if [l1,l2,l3]==[[4,3,2],[5,4,3],[9,7,5]]
end
binding.irb