443. 压缩字符串-python-双指针

题目：

思路：

定义两个指针：read和write

read用来遍历chars，write是用来记录压缩后的字符的存入位置

代码：

class Solution:
    def compress(self, chars: List[str]) -> int:
        #定义两个指针
        read=write=0
        n = len(chars)
        while read < n:
            cur = chars[read]
            count = 0
            while read < n and chars[read] == cur:
                read += 1
                count += 1
            #记录当前的字符
            chars[write]=cur
            write += 1
            if count > 1:
                # 把数字转成字符串，逐位写入
                for s in str(count):
                    chars[write]=s
                    write += 1
        return write