We say that a set of integers is closed by subtraction if, for every pair of distinct numbers in the set $$$a, b$$$, at least one of the two values $$$(a-b)$$$, $$$(b-a)$$$ also belongs to the set.
Given a set of integers, determine if it is closed by subtraction.
The first line contains an integer $$$T$$$, the number of test cases.
For each case, there is a line with an integer $$$n$$$, the number of elements in the set, followed by another line with $$$n$$$ integers $$$a_1, \ldots, a_n$$$, the numbers in the set. The $$$a_i$$$ are all distinct.
For each case, write a line with "SI" if the set is closed by subtraction and "NO" otherwise.
$$$1 \leq T \leq 100$$$.
$$$2 \leq n \leq 5 \cdot 10^5$$$, the sum of $$$n$$$ for all cases is less than $$$2 \cdot 10^6$$$.
$$$-10^9 \leq a_i \leq 10^9$$$ for $$$1 \leq i \leq n$$$.
40 points: $$$n \leq 100$$$, the sum of $$$n$$$ for all cases is less than $$$2000$$$.
25 points: $$$n \leq 2000$$$, the sum of $$$n$$$ for all cases is less than $$$2 \cdot 10^4$$$.
35 points: No additional restrictions.
5 3 1 2 3 4 5 4 0 2 3 -1 0 1 5 -4 -2 -6 -10 -8 2 1000000000 0
SI NO NO SI SI
