ruby problem of bonacci series

Question

code can be also found on this link https://code.sololearn.com/cva9U4w84M39/#rb
#bonacci series 0 0 0 0 1 1 2 4 8...
class Array_basic
def bonacci(n,m)
arr = Array.new
y = n-1 #here is problem if y = n-2 given

for i in 0..y #n... creates problem y = n-2 is also has problem
arr[i] = 0
end
arr << 1
#arr[3] = 1
#or use following
#arr <<1

for j in 1...m-n

arr[n+j] = 0
arr.values_at[n+j]
#or it doest not work
#arr[4..9] = 0 or arr[j] = 0

for k in 1...n
# puts "-- #{arr[n+j]} --- #{arr[n+j-k]}"
arr[n+j] = arr[n+j] + arr[n+j-k]

end
end
puts "-- >#{arr}"

end
end

obje = Array_basic.new
puts "Input n and m. n must smaller then m"
n = gets.to_i
m= gets.to_i
#bonacci series implemention call
obje.bonacci(n,m)
=begin
problem: on line 4 if y = n-1 given it is fully functional. if y = n-2 given then it says following on Console---
`+': nil can't be coerced into Integer (TypeError)

can anyone look that program where the actually problem is?
=end

Answer 1

You might want to save it as a code and give a link to it, just saying... ;)

EDIT: Yup, that's more like it.

Answer 2

The problem you have is that one of the values of your Array is an empty value (nil).

For example, with the values n = 10 and m = 12 your array contains the following values:

[0, 0, 0, 0, 0, 0, 0, 0, 0, 1, nil, 0, 0]

So when trying to execute the following line: arr [n + j] = arr [n + j] + arr [n + j - k] Ruby warns you that you can not add a number with a value of class Nil.

At this point I can only speculate that the nil value is generated in this case thanks to the operations with the Index of the arrays. Some of it is out of range in relation to the elements contained in the array.

Answer 3

It's strange, because I tried running it out of the class and still giving error. Btw, that serie that you put is part of the N-Bonacci numbers, right?

Although I recognize the series the way you try to generate it makes me confused

Answer 4

That code is easier to read. If you want to generate the series in base n - 2, you only have to make the range inclusive:

In your code you currently have it as for i in 0 ... n - 1 (that means you are excluding n - 1).

The exclusion generates an empty space when you start the iteration in the next cycle. One way to solve it could be to make the range inclusive: for i in 0..n - 2

Even so, I'm not entirely sure. I was able to generate all the series, including the range of your two cycles, but I still have some concerns.

(It also influences what is currently here 3:00 A.M. and I'm half asleep, lol)

Answer 5

now link is given

Answer 6

thanks... but this program when runs on without class-method. then it has no such as problem as i above mentioned.
but why within class menthod one index position becomes nil?

Answer 7

its a N-bonacci series.
try this link https://code.sololearn.com/cXlbCZ0ANW3Q/?ref=app