题解 | #字符串排序#

def f(c: str) -> bool:
    if c >= "a" and c <= "z":
        return True
    if c >= "A" and c <= "Z":
        return True
    return False


try:
    while True:
        s = [i for i in input()]
        n = len(s)
        if n == 0:
            print("")
            continue
        # print(s)
        dic = [[] for _ in range(26)]

        for c in s:
            if f(c):
                t = ord(c.lower()) - ord("a")
                dic[t].append(c)

        # print(dic)
        index, p = 0, 0
        # 移动到第一个不为空的地方
        while index < 26 and len(dic[index]) == 0:
            index += 1
        # 获取该字符出现的长度
        m = len(dic[index])

        # 枚举s字符串
        for i in range(n):
            # 非字母不动
            if not f(s[i]):
                continue
            if p < m:
                s[i] = dic[index][p]
                p += 1
            if p == m:
                # 重置指针
                p = 0
                # 移动到下一个不为空的字符集合
                index += 1
                while index < 26 and len(dic[index]) == 0:
                    index += 1
                if index < 26:
                    m = len(dic[index])
        print("".join(s))
except Exception:
    pass

哈希表存储

使用哈希表存储每个字符的出现顺序，最大也就26个。所以可以直接开26个数组用来存储。

再次遍历字符串，对字母位置的字符进行重新装填。