942. 增减字符串匹配

from typing import List


class Solution:
    def diStringMatch(self, s: str) -> List[int]:
        l, h, n, ret = 0, len(s), len(s), []
        for ch in s:
            if ch == 'I':
                ret.append(l)
                l += 1
            else:
                ret.append(h)
                h -= 1
        ret.append(l)
        return ret