1def search_insert(nums, target)
2  binary_search(nums, 0, nums.length-1) { |v| v - target }
3end
4
5def binary_search(arr, l, h, &proc)
6  if l <= h
7    mid = l + (h-l)/2
8    res = proc.call(arr[mid])
9    if res == 0
10      return mid
11    elsif res > 0 
12      return binary_search(arr, l, mid-1, &proc)
13    else 
14      return binary_search(arr, mid+1, h, &proc)
15    end
16  end
17  return l
18end