codeforces#P1789A. Serval and Mocha's Array
Serval and Mocha's Array
Description
Mocha likes arrays, and Serval gave her an array consisting of positive integers as a gift.
Mocha thinks that for an array of positive integers $a$, it is good iff the greatest common divisor of all the elements in $a$ is no more than its length. And for an array of at least $2$ positive integers, it is beautiful iff all of its prefixes whose length is no less than $2$ are good.
For example:
- $[3,6]$ is not good, because $\gcd(3,6)=3$ is greater than its length $2$.
- $[1,2,4]$ is both good and beautiful, because all of its prefixes whose length is no less than $2$, which are $[1,2]$ and $[1,2,4]$, are both good.
- $[3,6,1]$ is good but not beautiful, because $[3,6]$ is not good.
Now Mocha gives you the gift array $a$ of $n$ positive integers, and she wants to know whether array $a$ could become beautiful by reordering the elements in $a$. It is allowed to keep the array $a$ unchanged.
Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1\leq t\leq 500$). The 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 array $a$.
The second line of each test case contains $n$ integers $a_1,a_2,\ldots,a_n$ ($1\leq a_1,a_2,\ldots,a_n\leq 10^6$) — the elements of array $a$.
For each test case, print Yes if it is possible to reorder the elements in $a$ to make it beautiful, and print No if not.
You can output Yes and No in any case (for example, strings yEs, yes, Yes and YES will be recognized as a positive response).
Input
Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1\leq t\leq 500$). The 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 array $a$.
The second line of each test case contains $n$ integers $a_1,a_2,\ldots,a_n$ ($1\leq a_1,a_2,\ldots,a_n\leq 10^6$) — the elements of array $a$.
Output
For each test case, print Yes if it is possible to reorder the elements in $a$ to make it beautiful, and print No if not.
You can output Yes and No in any case (for example, strings yEs, yes, Yes and YES will be recognized as a positive response).
6
2
3 6
3
1 2 4
3
3 6 1
3
15 35 21
4
35 10 35 14
5
1261 227821 143 4171 1941
No
Yes
Yes
No
Yes
Yes
Note
In the first test case, neither $[3,6]$ nor $[6,3]$ are beautiful, so it's impossible to obtain a beautiful array by reordering the elements in $a$.
In the second test case, $[1,2,4]$ is already beautiful. Keeping the array $a$ unchanged can obtain a beautiful array.