8611: Yet Another Sorting Problem!

There are N persons in Bytetown, with the $i$-th person having an item of type A_i. These persons want to exchange items with each other through the following operation:

• Choose two persons i,j(i≠j), exchange the item owned by the $i$-th person and the j-th person.
  

They want to perform this operation exactly once between each pair of persons (i,j) with 1≤i<j≤N. At the end of this sequence of operations, the i-th person wants to own an item of type B_i. They want to know if there exists a sequence of operation achieving this requirement. Can you help them?

The first line contains an integer T (1≤T≤10⁴), denoting the number of test cases.
For each test case, the first line contains an integer N(1≤N≤200), denoting the number of persons in Bytetown.
The second line contains N integers A₁,A₂,…,A_N(1≤A_i≤N), where A_i denotes the item initially owned by the i-th person.
The third line contains N integers B₁,B₂,…,B_N(1≤B_i≤N), where B_i denotes the item desired by the i-th person.
It is guaranteed that the sum of N² does not exceed 4⋅10⁵.

For each test case, if there doesn't exist a sequence of operation achieving this requirement, output "NO"(without quotes) in a line. Otherwise, output "YES"(without quotes) in a line, then output a sequence of operation achieving the requirement in N(N−1)/2 lines, where the k(1≤k≤N(N−1)/2)th line contains two integers i,j, denoting the k-th operation in the sequence.

2
2
1 2
1 2
2
2 1
1 2

NO
YES
1 2