题解 | #表示数字#

非正则表达式最简单解法

s = list(input())
changed_s = s.copy()

for i in range(len(s)):
    # 数字的第一个字符
    if s[i].isdigit() and (not "".join(s[i - 1:i]).isdigit()):
        changed_s[i] = "*" + changed_s[i]

    # 数字的最后一个字符
    if s[i].isdigit() and (not "".join(s[i + 1:i + 2]).isdigit()):
        changed_s[i] = changed_s[i] + "*"

print("".join(changed_s))