Codeforces Round 821 (Div. 2) |
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Finished |
You are given an array $$$a$$$ with $$$n$$$ non-negative integers. You can apply the following operation on it.
Find any sequence of at most $$$n$$$ operations that makes $$$a$$$ non-decreasing. It can be proven that it is always possible. Note that you do not have to minimize the number of operations.
An array $$$a_1, a_2, \ldots, a_n$$$ is non-decreasing if and only if $$$a_1 \le a_2 \le \ldots \le a_n$$$.
The first line contains one integer $$$t$$$ ($$$1 \le t \le 10^5$$$) — the number of test cases.
Each test case consists of two lines. The first line of each test case contains one integer $$$n$$$ ($$$1 \le n \le 10^5$$$) — the length of the array.
The second line of each test case contains $$$n$$$ integers $$$a_1, a_2, \ldots, a_n$$$ ($$$0 \le a_i \le 10^9$$$) — the array itself.
It is guaranteed that the sum of $$$n$$$ over all test cases doesn't exceed $$$10^5$$$.
For each test case, print one integer $$$m$$$ ($$$0 \le m \le n$$$), the number of operations, in the first line.
Then print $$$m$$$ lines. Each line must contain two integers $$$l_i, r_i$$$, which are the indices you chose in the $$$i$$$-th operation ($$$1 \le l_i < r_i \le n$$$).
If there are multiple solutions, print any of them.
327 851 1000000000 3 0 510
0 2 3 4 1 2 0
In the second test case, $$$a$$$ changes like this:
In the first and third test cases, $$$a$$$ is already non-decreasing.
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