1370. Increasing Decreasing String 链接到标题 题目描述很复杂，但其实就是排序和字典，先顺序遍历再反向遍历。（熟练使用 Counter）Python 链接到标题 class Solution(object): def sortString(self, s): """ :type s: str :rtype: str """ set_s = set() for c in s: set_s.add(c) characters = sorted(set_s) d = collections.Counter(s) res = "" while sum(d.values……