#AT2544. D - Writing a Numeral
D - Writing a Numeral
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D - Writing a Numeral
Score : $400$ points
Problem Statement
We have a string $S$. Initially, $S=$ 1
.
Process $Q$ queries in the following formats in order.
1 x
: Append a digit $x$ at the end of $S$.2
: Delete the digit at the beginning of $S$.3
: Print the number represented by $S$ in decimal, modulo $998244353$.
Constraints
- $1 \leq Q \leq 6 \times 10^5$
- For each query in the first format, $x \in \{1,2,3,4,5,6,7,8,9\}$.
- A query in the second format is given only if $S$ has a length of $2$ or greater.
- There is at least one query in the third format.
Input
The input is given from Standard Input in the following format:
Here, $\mathrm{query}_i$ denotes the $i$-th query, which is in one of the following formats:
``` $1$ $x$ ``` ``` $2$ ``` ``` $3$ ```Output
Print $q$ lines, where $q$ is the number of queries in the third format. The $i$-th line $(1 \leq i \leq q)$ should correspond to the $i$-th query in the third format.
3
3
1 2
3
1
12
In the first query, $S$ is 1
, so you should print $1$ modulo $998244353$, that is, $1$.
In the second query, $S$ becomes 12
.
In the third query, $S$ is 12
, so you should print $12$ modulo $998244353$, that is, $12$.
3
1 5
2
3
5
11
1 9
1 9
1 8
1 2
1 4
1 4
1 3
1 5
1 3
2
3
0
Be sure to print numbers modulo $998244353$.