## Description

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

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.

**Example 1:**

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

**Example 2:**

Input:s = "abbcccddddeeeeedcba"Output:5Explanation:The substring "eeeee" is of length 5 with the character 'e' only.

**Example 3:**

Input:s = "triplepillooooow"Output:5

**Example 4:**

Input:s = "hooraaaaaaaaaaay"Output:11

**Example 5:**

Input:s = "tourist"Output:1

**Constraints:**

`1 <= s.length <= 500`

`s`

contains only lowercase English letters.

## Explanation

count max consecutive substring with only one unique character.

## Python Solution

```
class Solution:
def maxPower(self, s: str) -> int:
longest = 0
count = 0
prev = None
for i, c in enumerate(s):
if c == prev:
count += 1
else:
longest = max(longest, count)
prev = c
count = 1
return max(longest, count)
```

- Time Complexity: O(N).
- Space Complexity: O(1).