The challenge:
Input: [6, 2, 3, 8]
Output: 3
To explain better the input and output relationship I need to sort the numbers first
[2,3,6,8]
You see that the numbers that are missing are 4,5, and 7.
How many numbers are missing? Exactly, 3. 3 is the answer.
Input: [0, 3]
Output: 2
Input: [5, 4, 6]
Output: 0
Input: [2]
Output: 0
The link to the challenge
An invite link to join CodeSignal
My first attempt:
defmodule MakeArrayConsecutive do
# statues = [6, 2, 3, 8]
# makeArrayConsecutive2(statues) = 3
def makeArrayConsecutive2(statues) do
statues
|> Enum.sort()
|>
end
# What am I trying to do here?
defp number_of_holes(sorted_list) do
Enum.reduce(list, [],
fn(x, []) ->
[x]
end
fn(x, [head | tail] = whole_list) ->
if x - head =
end
)
end
end
My second attempt, still not the full solution, but very close. I didn't account the case [0,3].
defmodule MakeArrayConsecutive do
# statues = [6, 2, 3, 8]
# makeArrayConsecutive2(statues) = 3
def makeArrayConsecutive2(statues) do
case check_singleton(statues) do
0 ->
0
list ->
list
|> Enum.sort()
|> number_of_holes()
|> return_difference()
end
end
defp check_singleton(xs) do
case xs do
[x] -> 0
list -> list
end
end
defp return_difference({x, y}) do
y
end
defp number_of_holes(sorted_list) do
Enum.reduce(sorted_list, {0, 0}, fn(x, acc) ->
case acc do
{0,0} ->
{x, 0}
{number, difference} ->
if x - number <= 1 do
{x, difference}
else
{x, difference + (x - number - 1)}
end
end
end)
end
end
Top comments (1)
And final solution, which as admittedly very verbose.