Discussion on: Daily Challenge #60 - Find the Missing Letter

[Melvin Yeo]

I wrote the code (in Python) assuming that the missing letter is within the list, if not there would be 2 answers to it.

def missing_letter(input):
    for index in range(len(input) - 1):
        if ord(input[index + 1]) - ord(input[index]) != 1:
            return chr(ord(input[index]) + 1)

Here is my previous implementation, I wrote this to handle the scenario that the input list wasn't in an ascending order (I didn't read the question completely 🤣)

def missing_letter(input):
    arr = [input[0]] + [None] * len(input)

    for elem in input[1:]:
        if elem < arr[0]:
            offset = elem - arr[0]
            arr = arr[offset::] + arr[:offset]
            arr[0] = elem
        else:
            arr[ord(elem) - ord(arr[0])] = elem

    for index, elem in enumerate(arr):
        if elem is None:
            return chr(ord(arr[0]) + index)