C - Ubiquity
该比赛已结束,您无法在比赛模式下递交该题目。您可以点击“在题库中打开”以普通模式查看和递交本题。
C - Ubiquity
Score : $300$ points
Problem Statement
How many integer sequences $A_1,A_2,\ldots,A_N$ of length $N$ satisfy all of the following conditions?
- $0 \leq A_i \leq 9$
- There exists some $i$ such that $A_i=0$ holds.
- There exists some $i$ such that $A_i=9$ holds.
The answer can be very large, so output it modulo $10^9 + 7$.
Constraints
- $1 \leq N \leq 10^6$
- $N$ is an integer.
Input
Input is given from Standard Input in the following format:
Output
Print the answer modulo $10^9 + 7$.
2
2
Two sequences $\{0,9\}$ and $\{9,0\}$ satisfy all conditions.
1
0
869121
2511445