Codeforces Round 904 (Div. 2) |
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Finished |
You are given an array of integers $$$a_1, a_2, \ldots, a_n$$$.
A pair of integers $$$(i, j)$$$, such that $$$1 \le i < j \le n$$$, is called good, if there does not exist an integer $$$k$$$ ($$$1 \le k \le n$$$) such that $$$a_i$$$ is divisible by $$$a_k$$$ and $$$a_j$$$ is divisible by $$$a_k$$$ at the same time.
Please, find the number of good pairs.
Each test contains multiple test cases. The first line contains the number of test cases $$$t$$$ ($$$1 \le t \le 2 \cdot 10^4$$$). The description of the test cases follows.
The first line of each test case contains a single integer $$$n$$$ ($$$1 \le n \le 10^6$$$).
The second line of each test case contains $$$n$$$ integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \le a_i \le n$$$).
It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$10^6$$$.
For each test case, output the number of good pairs.
642 4 4 442 3 4 496 8 9 4 6 8 9 4 997 7 4 4 9 9 6 2 91810 18 18 15 14 4 5 6 8 9 10 12 15 16 18 17 13 112112 19 19 18 18 12 2 18 19 12 12 3 12 12 12 18 19 16 18 19 12
0 3 26 26 124 82
In the first test case, there are no good pairs.
In the second test case, here are all the good pairs: $$$(1, 2)$$$, $$$(2, 3)$$$, and $$$(2, 4)$$$.
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