题解 | 字符串加解密

import sys

def decode(s):
    ans = []
    for s_ in s:
        if s_.isdigit():
            ans.append(str((int(s_)+9) % 10))
        elif s_.isupper():
            ans.append(chr(ord('a') + (ord(s_.lower())-ord('a')+25) % 26))
        elif s_.islower():
            ans.append(chr(ord('A') + (ord(s_.upper())-ord('A')+25) % 26))
    return "".join(ans)

def code(s):
    ans = []
    for s_ in s:
        if s_.isdigit():
            ans.append(str((int(s_)+1) % 10))
        elif s_.isupper():
            ans.append(chr(ord('a') + (ord(s_.lower())-ord('a')+1) % 26))
        elif s_.islower():
            ans.append(chr(ord('A') + (ord(s_.upper())-ord('A')+1) % 26))
    return "".join(ans)

print(code(input()))
print(decode(input()))