题目描述
Alice and Bob came up with a rather strange game. They have an array of integers $a_1, a_2,\ldots, a_n$. Alice chooses a certain integer $k$ and tells it to Bob, then the following happens:
- Bob chooses two integers $i$ and $j$ ($1 \le i < j \le n$), and then finds the maximum among the integers $a_i, a_{i + 1},\ldots, a_j$;
- If the obtained maximum is strictly greater than $k$, Alice wins, otherwise Bob wins.
Help Alice find the maximum $k$ at which she is guaranteed to win.
Input
Each test consists of multiple test cases. The first line contains a single integer $t$ ($1 \le t \le 10^4$) — the number of test cases. The description of the test cases follows.
The first line of each test case contains a single integer $n$ ($2 \le n \le 5 \cdot 10^4$) — the number of elements in the array.
The second line of each test case contains $n$ integers $a_1, a_2,\ldots, a_n$ ($1 \le a_i \le 10^9$) — the elements of the array.
It is guaranteed that the sum of $n$ over all test cases does not exceed $5 \cdot 10^4$.
Output
For each test case, output one integer — the maximum integer $k$ at which Alice is guaranteed to win.
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 test case, all possible subsegments that Bob can choose look as follows: $[2, 4], [2, 4, 1], [2, 4, 1, 7], [4, 1], [4, 1, 7], [1, 7]$. The maximums on the subsegments are respectively equal to $4, 4, 7, 4, 7, 7$. It can be shown that $3$ is the largest integer such that any of the maximums will be strictly greater than it.
In the third test case, the only segment that Bob can choose is $[1, 1]$. So the answer is $0$.