Delete key

Given a key, delete all occurrences of it from the array

Example

delete_key([5,1,6,3,4,5,8,3,5], 5) #=> [1,6,3,4,8,3]
delete_key([5], 5) #=> []

Solution

• Traverse the array, use a read and write index, skip over all the elements that match the key

Code

def delete_key(arr, key)
  read = 0
  write = 0

  while(read < arr.size)
    if(arr[read] != key)
      arr[write] = arr[read]
      write += 1
    end
    read += 1
  end

  arr[0..write-1]
end

Complexity

Time: O(n), single traversal over the array Space: Constant space