题解 | #表示数字#

方法一：

while True:
    try:
        s=input()
        s='a'+s+'a'
        t=''
        for i in range(1,len(s)-1):
            if s[i].isdigit():
                if not s[i-1].isdigit() and not s[i+1].isdigit():
                    t+='*'+s[i]+'*'
                elif not s[i-1].isdigit():
                    t+='*'+s[i]
                elif not s[i+1].isdigit():
                    t+=s[i]+'*'
                else:
                    t+=s[i]
            else:
                t+=s[i]
        print(t)
    except:
        break
                    

方法二（参照）：

while True:
    try:
        char_str = input()
        pre_char =''
        s=''
        for i in char_str:
            if i.isdigit():
                if not pre_char.isdigit():
                    s+='*'
            else:
                if pre_char.isdigit():
                    s+='*'
            s+=i
            pre_char=i
        if char_str[-1].isdigit():
            s+='*'
        print(s)
    except:
        break