第一题流浪者

//众所周知..MozhuCY师傅么得雪币，文章由我代发

一个单表替换,输入范围是0-9,a-z,A-Z,分别对应表的0 - 9,10 - 35,36 - 61

table = "abcdefghiABCDEFGHIJKLMNjklmn0123456789opqrstuvwxyzOPQRSTUVWXYZ"
s = "KanXueCTF2019JustForhappy"
ff = []
for i in s:
    ff.append(table.index(i))
 
flag = ""
for i in ff:
    if 0 <= i <= 9:
        flag += chr(i + 48)
    elif 9 < i <= 35:
        flag += chr(i + 87)
    elif i > 36:
        flag += chr(i + 29)
 
print flag