Consecutive Characters

https://leetcode.com/problems/consecutive-characters/

Question

Given a string s, the power of the string is the maximum length of a non-empty substring that contains only one unique character.

Return the power of the string.

Input: s = "leetcode"
Output: 2
Explanation: The substring "ee" is of length 2 with the character 'e' only.

Answer

class Solution:
    def maxPower(self, s: str) -> int:
        powers = [None for x in range(len(s))]
        powers[0] = 1
        for i in range(1, len(powers)):
            if s[i] == s[i - 1]:
                powers[i] = powers[i - 1] + 1
            else:
                powers[i] = 1
        return max(powers)

We generate a list of all possible powers.

The base case is:

• [0] = 1, since there are no letters before.

And then for each power, it is either:

• The previous power + 1 (because its a continuation of the substring + 1 char since the chars are the same)

aaab
[4, 5]
i[2] = i[2 - 1] + 1 because "a" at index 2 == "a" at index 1.

• 1, because it's a new substring

We then return the maximum possible value over our array.