Codeforces Round 724 (Div. 2) |
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Finished |
Omkar has received a message from Anton saying "Your story for problem A is confusing. Just make a formal statement." Because of this, Omkar gives you an array $$$a = [a_1, a_2, \ldots, a_n]$$$ of $$$n$$$ distinct integers. An array $$$b = [b_1, b_2, \ldots, b_k]$$$ is called nice if for any two distinct elements $$$b_i, b_j$$$ of $$$b$$$, $$$|b_i-b_j|$$$ appears in $$$b$$$ at least once. In addition, all elements in $$$b$$$ must be distinct. Can you add several (maybe, $$$0$$$) integers to $$$a$$$ to create a nice array $$$b$$$ of size at most $$$300$$$? If $$$a$$$ is already nice, you don't have to add any elements.
For example, array $$$[3, 6, 9]$$$ is nice, as $$$|6-3|=|9-6| = 3$$$, which appears in the array, and $$$|9-3| = 6$$$, which appears in the array, while array $$$[4, 2, 0, 6, 9]$$$ is not nice, as $$$|9-4| = 5$$$ is not present in the array.
For integers $$$x$$$ and $$$y$$$, $$$|x-y| = x-y$$$ if $$$x > y$$$ and $$$|x-y| = y-x$$$ otherwise.
Each test contains multiple test cases. The first line contains $$$t$$$ ($$$1 \leq t \leq 50$$$), the number of test cases. Description of the test cases follows.
The first line of each test case contains a single integer $$$n$$$ ($$$2 \leq n \leq 100$$$) — the length of the array $$$a$$$.
The second line of each test case contains $$$n$$$ distinct integers $$$a_1, a_2, \cdots, a_n$$$ ($$$-100 \leq a_i \leq 100$$$) — the elements of the array $$$a$$$.
For each test case, output one line containing YES if Omkar can create a nice array $$$b$$$ by adding elements to $$$a$$$ and NO otherwise. The case of each letter does not matter, so yEs and nO will also be accepted.
If the first line is YES, output a second line containing a single integer $$$k$$$ ($$$n \leq k \leq 300$$$).
Then output one line containing $$$k$$$ distinct integers $$$b_1, b_2, \cdots, b_k$$$ ($$$-10^9 \leq b_i \leq 10^9$$$), the elements of the nice array $$$b$$$. $$$b_1, b_2, \cdots, b_k$$$ can be in any order. For each $$$a_i$$$ in $$$a$$$, $$$a_i$$$ must appear at least once in $$$b$$$.
It can be proved that if Omkar can create such an array $$$b$$$, then he can also do so in a way that satisfies the above constraints.
If multiple solutions exist, you can print any.
4 3 3 0 9 2 3 4 5 -7 3 13 -2 8 4 4 8 12 6
yes 4 6 0 3 9 yEs 5 5 3 1 2 4 NO Yes 6 8 12 6 2 4 10
For the first case, you can add integers to $$$a$$$ to receive the array $$$b = [6, 0, 3, 9]$$$. Note that $$$|6-3| = |9-6| = |3-0| = 3$$$ and $$$3$$$ is in $$$b$$$, $$$|6-0| = |9-3| = 6$$$ and $$$6$$$ is in $$$b$$$, and $$$|9-0| = 9$$$ is in $$$b$$$, so $$$b$$$ is nice.
For the second case, you can add integers to $$$a$$$ to receive the array $$$b = [5, 3, 1, 2, 4]$$$. We have that $$$|2-1| = |3-2| = |4-3| = |5-4| = 1$$$ is in $$$b$$$, $$$|3-1| = |4-2| = |5-3| = 2$$$ is in $$$b$$$, $$$|4-1| = |5-2| = 3$$$ is in $$$b$$$, and $$$|5-1| = 4$$$ is in $$$b$$$, so $$$b$$$ is nice.
For the fourth case, you can add integers to $$$a$$$ to receive the array $$$b = [8, 12, 6, 2, 4, 10]$$$. We have that $$$|4-2| = |6-4| = |8-6| = |10-8| = |12-10| = 2$$$ is in $$$b$$$, $$$|6-2| = |8-4| = |10-6| = |12-8| = 4$$$ is in $$$b$$$, $$$|8-2| = |10-4| = |12-6| = 6$$$ is in $$$b$$$, $$$|10-2| = |12-4| = 8$$$ is in $$$b$$$, and $$$|12-2| = 10$$$ is in $$$b$$$, so $$$b$$$ is nice.
It can be proven that for all other test cases it is impossible to create a nice array $$$b$$$.
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