#abc201c. C - Secret Number
C - Secret Number
Score : points
问题描述
高桥忘记了他四位数的 PIN 码。该 PIN 码由 0
, 1
, , 9
组成,且可能以 0
开头。
对于数字 0
到 9
,高桥记住了以下事实,用一个包含 个字符的字符串 表示:
- 如果 是
o
:他确定 PIN 码中包含数字 ; - 如果 是
x
:他确定 PIN 码中不包含数字 ; - 如果 是
?
:他不确定 PIN 码中是否包含数字 。
有多少个字符串可能是高桥的 PIN 码?
以上为通义千问 qwen-max 翻译,仅供参考。
Problem Statement
Takahashi has forgotten his PIN. The PIN is a four-digit string consisting of 0
, 1
, , 9
, and may begin with a 0
.
For each digit 0
through 9
, Takahashi remembers the following fact, represented by a -character string :
- if is
o
: he is certain that the PIN contained the digit ; - if is
x
: he is certain that the PIN did not contain the digit ; - if is
?
: he is not sure whether the PIN contained the digit .
How many strings are there that could be Takahashi's PIN?
Constraints
- is a -character string consisting of
o
,x
, and?
.
Input
Input is given from Standard Input in the following format:
Output
Print the answer.
Sample Input 1
ooo???xxxx
Sample Output 1
108
Some of the possible PINs are 0123
and 0021
.
Sample Input 2
o?oo?oxoxo
Sample Output 2
0
There may be no possible PINs, in which case the answer is .
Sample Input 3
xxxxx?xxxo
Sample Output 3
15
update @ 2024/3/10 09:12:57