题解 | #自守数#
自守数
https://www.nowcoder.com/practice/88ddd31618f04514ae3a689e83f3ab8e?tpId=37&tqId=21322&rp=1&ru=/exam/oj/ta&qru=/exam/oj/ta&sourceUrl=%2Fexam%2Foj%2Fta%3FtpId%3D37&difficulty=undefined&judgeStatus=undefined&tags=&title=99
n = int(input()) count = 0 # 用于取余 mod = 10 for i in range(n+1): if mod < i: mod *= 10 if i ** 2 % mod == i: count += 1 print(count)