A9626. Substitutes in Number
编程题
普及/提高-
知识点
题目描述
Andrew and Eugene are playing a game. Initially, Andrew has string $s$ , consisting of digits. Eugene sends Andrew multiple queries of type " $d_{i}→t_{i}$ ", that means "replace all digits $d_{i}$ in string $s$ with substrings equal to $t_{i}$ ". For example, if $s=123123$ , then query " $2→00$ " transforms $s$ to $10031003$ , and query " $3→$ " ("replace 3 by an empty string") transforms it to $s=1212$ . After all the queries Eugene asks Andrew to find the remainder after division of number with decimal representation equal to $s$ by $1000000007 (10^{9}+7)$ . When you represent $s$ as a decimal number, please ignore the leading zeroes; also if $s$ is an empty string, then it's assumed that the number equals to zero.
Andrew got tired of processing Eugene's requests manually and he asked you to write a program for that. Help him!
Andrew got tired of processing Eugene's requests manually and he asked you to write a program for that. Help him!
输入格式
The first line contains string $s$ ( $1<=|s|<=10^{5}$ ), consisting of digits — the string before processing all the requests.
The second line contains a single integer $n$ ( $0<=n<=10^{5}$ ) — the number of queries.
The next $n$ lines contain the descriptions of the queries. The $i$ -th query is described by string " $d_{i}$ -> $t_{i}$ ", where $d_{i}$ is exactly one digit (from 0 to 9), $t_{i}$ is a string consisting of digits ( $t_{i}$ can be an empty string). The sum of lengths of $t_{i}$ for all queries doesn't exceed $10^{5}$ . The queries are written in the order in which they need to be performed.
The second line contains a single integer $n$ ( $0<=n<=10^{5}$ ) — the number of queries.
The next $n$ lines contain the descriptions of the queries. The $i$ -th query is described by string " $d_{i}$ -> $t_{i}$ ", where $d_{i}$ is exactly one digit (from 0 to 9), $t_{i}$ is a string consisting of digits ( $t_{i}$ can be an empty string). The sum of lengths of $t_{i}$ for all queries doesn't exceed $10^{5}$ . The queries are written in the order in which they need to be performed.
输出格式
Print a single integer — remainder of division of the resulting number by $1000000007 (10^{9}+7)$ .
输入输出样例
输入 #1
123123 1 2->00
输出 #1
10031003
输入 #2
123123 1 3->
输出 #2
1212
输入 #3
222 2 2->0 0->7
输出 #3
777
输入 #4
1000000008 0
输出 #4
1
说明/提示
Note that the leading zeroes are not removed from string $s$ after the replacement (you can see it in the third sample).