题解 | 字符串排序

s = input()
letters = [c for c in s if c.isalpha()]
sorted_l = sorted(letters,key=str.lower)
cnt = 0
res = ""
for i in range(0,len(s)):
    c = s[i]
    if c.isalpha():
        res = res + sorted_l[cnt]
        cnt = cnt + 1
    else:
        res = res + c
print(res)