201410: [AtCoder]ARC141 A - Periodic Number
Description
Score : $400$ points
Problem Statement
For a positive integer $n$, let $\mathrm{str}(n)$ be the string representing $n$ in decimal.
We say that a positive integer $n$ is periodic when there exists a positive integer $m$ such that $\mathrm{str}(n)$ is the concatenation of two or more copies of $\mathrm{str}(m)$. For example, $11$, $1212$, and $123123123$ are periodic.
You are given a positive integer $N$ at least $11$. Find the greatest periodic number at most $N$. It can be proved that there is at least one periodic number at most $N$.
You will get $T$ test cases to solve.
Constraints
- $1 \leq T \leq 10^4$
- $11 \leq N < 10^{18}$
- All values in input are integers.
Input
Input is given from Standard Input in the following format:
$T$ $\mathrm{case}_1$ $\vdots$ $\mathrm{case}_T$
Each case is given in the following format:
$N$
Output
Print $T$ lines. The $i$-th line should contain the answer for the $i$-th test case.
Sample Input 1
3 1412 23 498650499498649123
Sample Output 1
1313 22 498650498650498650
For the first test case, the periodic numbers at most $1412$ include $11$, $222$, $1212$, $1313$, and the greatest is $1313$.