Codeforces Round 781 (Div. 2) |
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Finished |
You are given an array $$$a$$$ of $$$n$$$ integers. Initially there is only one copy of the given array.
You can do operations of two types:
You need to find the minimal number of operations needed to obtain a copy where all elements are equal.
The input consists of multiple test cases. The first line contains a single integer $$$t$$$ ($$$1 \le t \le 10^4$$$) — the number of test cases. Description of the test cases follows.
The first line of each test case contains a single integer $$$n$$$ ($$$1 \le n \le 10^5$$$) — the length of the array $$$a$$$.
The second line of each test case contains $$$n$$$ integers $$$a_1, a_2, \ldots, a_n$$$ ($$$-10^9 \le a_i \le 10^9$$$) — the elements of the array $$$a$$$.
It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$10^5$$$.
For each test case output a single integer — the minimal number of operations needed to create at least one copy where all elements are equal.
61178960 1 3 3 7 02-1000000000 100000000044 3 2 152 5 7 6 371 1 1 1 1 1 1
0 6 2 5 7 0
In the first test case all elements in the array are already equal, that's why the answer is $$$0$$$.
In the second test case it is possible to create a copy of the given array. After that there will be two identical arrays:
$$$[ \ 0 \ 1 \ 3 \ 3 \ 7 \ 0 \ ]$$$ and $$$[ \ 0 \ 1 \ 3 \ 3 \ 7 \ 0 \ ]$$$
After that we can swap elements in a way so all zeroes are in one array:
$$$[ \ 0 \ \underline{0} \ \underline{0} \ 3 \ 7 \ 0 \ ]$$$ and $$$[ \ \underline{1} \ 1 \ 3 \ 3 \ 7 \ \underline{3} \ ]$$$
Now let's create a copy of the first array:
$$$[ \ 0 \ 0 \ 0 \ 3 \ 7 \ 0 \ ]$$$, $$$[ \ 0 \ 0 \ 0 \ 3 \ 7 \ 0 \ ]$$$ and $$$[ \ 1 \ 1 \ 3 \ 3 \ 7 \ 3 \ ]$$$
Let's swap elements in the first two copies:
$$$[ \ 0 \ 0 \ 0 \ \underline{0} \ \underline{0} \ 0 \ ]$$$, $$$[ \ \underline{3} \ \underline{7} \ 0 \ 3 \ 7 \ 0 \ ]$$$ and $$$[ \ 1 \ 1 \ 3 \ 3 \ 7 \ 3 \ ]$$$.
Finally, we made a copy where all elements are equal and made $$$6$$$ operations.
It can be proven that no fewer operations are enough.
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