一个解密小游戏有人会吗

Question

这是加密方式
第一个字母向后推一位，第二个字母向后推两位，以此类推
在第二十六个字母时重置为向后推一位
在第五十二个字母时再度重置为向后推一位
以此类推

Icyi dub pnkcp? Gvthv al u bdlqs jpvmik apn ycsnbxprlbii. Pec fiqvx mgz prqs mahx hvuhhiwfqrbpfi fchznxpef oct jmkpzeijzoeh egosqci. Hq nft qcd fiieqmqff. L lfbl bx edq gvxi dwmbjz qm hohrvr evc Frz'e gvt cfdx?

帮忙解一下密

Answer 1

我知道了

pwd = input()
res = ''
pos = 1
for i in pwd:
    if i.isalpha():
        n = ord(i)-pos
        if i.islower():
            if n < 97: n+=26
        else:
            if n < 65: n+=26
        i = chr(n)
        pos += 1
        if pos>25:pos=1
    res+=i
print(res)

Icyi dub pnkcp? Gvthv al u bdlqs jpvmik apn ycsnbxprlbii. Pec fiqvx mgz prqs mahx hvuhhiwfqrbpfi fchznxpef oct jmkpzeijzoeh egosqci. Hq nft qcd fiieqmqff. L lfbl bx edq gvxi dwmbjz qm hohrvr evc Frz'e gvt cfdx?
Have you heard? There is a ghost inside the organization. The ghost has high anti reconnaissance awareness and surveillance ability. We are all monitored. I have to use this method to inform you Who's the mole?