Changing a value in an array of random numbers in a loop - ruby

Question

I'm trying to make a loop that when the random number matches the same index of the input the value is changed and stays that way for each following loop.
input = gets.chomp
tries_left = 12
while(tries_left > 0)
tries_left -= 1
computer = 4.times.map do rand(0..6) end.join
if computer[0] == input[0]
computer[0] = input[0]
end
end
in the code above after the first loop the value stored to input[0] resets.
computer = 4.times.map do rand(0..6) end.join
input = gets.chomp
tries_left = 12
while(tries_left > 0)
tries_left -= 1
if computer[0] == input[0]
computer[0] = input[0]
end
if I take computer out of the loop like this, it will have the same random number generated each time. Once again I need it to generate new numbers each time besides what was already a match.

Answer 1

If you make the computer an array of strings, you can freeze it to prevent further modifications to it, and then replace the contents in computer when it doesn't match the index:
input = gets.chomp
tries_left = 12
computer = Array.new(4) { '' }
# setting the srand to 1234, the next 48 calls to 'rand(0..6)' will always
# result in the following sequence:
# 3, 6, 5, 4, 4, 0, 1, 1, 1, 2, 6, 3, 6, 4, 4, 2, 6, 2, 0, 0, 4, 5, 0, 1,
# 6, 6, 2, 0, 3, 4, 5, 2, 6, 2, 3, 3, 0, 1, 3, 0, 3, 2, 3, 4, 1, 3, 3, 3
# this is useful for testing things are working correctly,
# but take it out for 'live' code
srand 1234
while tries_left > 0
# no need to keep iterating if we've generated all the correct values
if computer.all?(&:frozen?)
puts "won #{computer.inspect} in #{12 - tries_left} tries"
break
end
tries_left -= 1
computer.each.with_index do |random, index|
# generate a new random number here unless they guessed correctly previously
random.replace(rand(0..6).to_s) unless random.frozen?
# if they've guessed the new random number, mark the string so they we
# don't update it
random.freeze if random == input[index]
end
puts "#{computer.inspect} has #{computer.count(&:frozen?)} correct numbers"
end
and then when you run the script:
$ echo 3654 | ruby example.rb
# ["3", "6", "5", "4"] has 4 correct numbers
# won ["3", "6", "5", "4"] in 1 tries
$ echo 3644 | ruby example.rb
# ["3", "6", "5", "4"] has 3 correct numbers
# ["3", "6", "4", "4"] has 4 correct numbers
# won ["3", "6", "4", "4"] in 2 tries
$ echo 3555 | ruby example.rb
# ["3", "6", "5", "4"] has 2 correct numbers
# ["3", "4", "5", "0"] has 2 correct numbers
# ["3", "1", "5", "1"] has 2 correct numbers
# ["3", "1", "5", "2"] has 2 correct numbers
# ["3", "6", "5", "3"] has 2 correct numbers
# ["3", "6", "5", "4"] has 2 correct numbers
# ["3", "4", "5", "2"] has 2 correct numbers
# ["3", "6", "5", "2"] has 2 correct numbers
# ["3", "0", "5", "0"] has 2 correct numbers
# ["3", "4", "5", "5"] has 3 correct numbers
# ["3", "0", "5", "5"] has 3 correct numbers
# ["3", "1", "5", "5"] has 3 correct numbers

Answer 2

It’s not quite clear what you are trying to accomplish, but this:
if computer[0] == input[0]
computer[0] = input[0]
end
is obviously a noop. Nothing gets updated, since the computer[0], whatever it is, is being set to the same value it was. I believe you wanted to somehow use an index in the array:
4.times.map do |index|
value = rand(0..6)
# somehow check the similarity, e.g.:
if input[index] == value
# do something
end
end
I beg your pardon for the very vague answer, but it is really hard to understand the goal you are trying to achieve.