题目描述
Tenzing has $n$ balls arranged in a line. The color of the $i$-th ball from the left is $a_i$.
Tenzing can do the following operation any number of times:
- select $i$ and $j$ such that $1\leq i < j \leq |a|$ and $a_i=a_j$,
- remove $a_i,a_{i+1},\ldots,a_j$ from the array (and decrease the indices of all elements to the right of $a_j$ by $j-i+1$).
Tenzing wants to know the maximum number of balls he can remove.
Input
Each test contains multiple test cases. The first line of input contains a single integer $t$ ($1\leq t\leq 10^3$) — the number of test cases. The description of test cases follows.
The first line contains a single integer $n$ ($1\leq n\leq 2\cdot 10^5$) — the number of balls.
The second line contains $n$ integers $a_1,a_2,\ldots,a_n$ ($1\leq a_i \leq n$) — the color of the balls.
It is guaranteed that sum of $n$ of all test cases will not exceed $2\cdot 10^5$.
Output
For each test case, output the maximum number of balls Tenzing can remove.
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分
样例输入
样例输出
提示
In the first example, Tenzing will choose $i=2$ and $j=3$ in the first operation so that $a=[1,3,3]$. Then Tenzing will choose $i=2$ and $j=3$ again in the second operation so that $a=[1]$. So Tenzing can remove $4$ balls in total.
In the second example, Tenzing will choose $i=1$ and $j=3$ in the first and only operation so that $a=[2]$. So Tenzing can remove $3$ balls in total.