codeforces#P1861D. Sorting By Multiplication

Sorting By Multiplication

Description

You are given an array $a$ of length $n$, consisting of positive integers.

You can perform the following operation on this array any number of times (possibly zero):

  • choose three integers $l$, $r$ and $x$ such that $1 \le l \le r \le n$, and multiply every $a_i$ such that $l \le i \le r$ by $x$.

Note that you can choose any integer as $x$, it doesn't have to be positive.

You have to calculate the minimum number of operations to make the array $a$ sorted in strictly ascending order (i. e. the condition $a_1 < a_2 < \dots < a_n$ must be satisfied).

The first line contains a single integer $t$ ($1 \le t \le 10^4$)  — the number of test cases.

The first line of each test case contains one integer $n$ ($1 \le n \le 2 \cdot 10^5$)  — the length of the array $a$.

The second line of each test case contains $n$ integers $a_1, a_2, \dots, a_n$ ($1 \le a_i \le 10^9$) — the array $a$.

Additional constraint on the input: the sum of $n$ over all test cases does not exceed $2 \cdot 10^5$.

For each test case, print one integer — the minimum number of operations required to make $a$ sorted in strictly ascending order.

Input

The first line contains a single integer $t$ ($1 \le t \le 10^4$)  — the number of test cases.

The first line of each test case contains one integer $n$ ($1 \le n \le 2 \cdot 10^5$)  — the length of the array $a$.

The second line of each test case contains $n$ integers $a_1, a_2, \dots, a_n$ ($1 \le a_i \le 10^9$) — the array $a$.

Additional constraint on the input: the sum of $n$ over all test cases does not exceed $2 \cdot 10^5$.

Output

For each test case, print one integer — the minimum number of operations required to make $a$ sorted in strictly ascending order.

3
5
1 1 2 2 2
6
5 4 3 2 5 1
3
1 2 3
3
2
0

Note

In the first test case, we can perform the operations as follows:

  • $l = 2$, $r = 4$, $x = 3$;
  • $l = 4$, $r = 4$, $x = 2$;
  • $l = 5$, $r = 5$, $x = 10$.
After these operations, the array $a$ becomes $[1, 3, 6, 12, 20]$.

In the second test case, we can perform one operation as follows:

  • $l = 1$, $r = 4$, $x = -2$;
  • $l = 6$, $r = 6$, $x = 1337$.
After these operations, the array $a$ becomes $[-10, -8, -6, -4, 5, 1337]$.

In the third test case, the array $a$ is already sorted.