ruby - Why is my version of bsearch not working? -

i running bsearch([1,2,3,4,5,6], 6)

this version of bsearch:

def bsearch(arr, target)      return nil if arr.size == 0      half = arr.size / 2     left = arr[0...half]     right = arr[half...-1]      case target <=> arr[half]     when 1       return half + bsearch(right, target)     when 0       return half     when -1       return bsearch(left, target)     end end 

this error being thrown:

recursion.rb:224:in `+': nil can't coerced fixnum (typeerror)     recursion.rb:224:in `bsearch'     recursion.rb:224:in `bsearch'     recursion.rb:249:in `<main>' 

from ruby docs:

.. run beginning end inclusively. created using ... exclude end value

your code excluding final array element.

left = arr[0...half] right = arr[half...-1] 

change use range operator .. instead of ...

left = arr[0..half] right = arr[half..-1]