Problem statement

https://binarysearch.com/problems/Longest-Alliteration/

Solution

Create array of the first letters, then use groupby.

Complexity

It is O(n) for time and space, where n is the total length of all words.

Code

class Solution:
    def solve(self, words):
        x = [w[0] for w in words]
        ans = 0
        for x, y in groupby(x):
            ans = max(ans, len(list(y)))
        return ans