【leetcode】1446. Consecutive Characters

题目如下：

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: 2
Explanation: The substring "ee" is of length 2 with the character 'e' only.
Example 2:
Input: s = "abbcccddddeeeeedcba"
Output: 5
Explanation: 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.

解题思路：送分题。

代码如下：

class Solution(object):
    def maxPower(self, s):
        """
        :type s: str
        :rtype: int
        """
        last = None
        res = 1
        count = 0
        for i in range(len(s)):
            if last == None:
                last = s[i]
                count = 1
            elif last == s[i]:
                count += 1
                res = max(count,res)
            else:
                count = 1
                last = s[i]
        return res