Hamburger String

BUG is a famous burger shop. Lots of costumers wait for burgers outside the burger every morning, because those hamburgers are so unforgettable.
Costumers stand in a queue, they come one by one, the latest one join into the end.
When a costumer(A) come to the end of the queue, if there’s already someone(B), wearing the same color as him, people between them(including A and B, called Hamburger String) will be served.
Served people leave the queue immediately.
N people come one by one, given their colors, can you tell me how many Hamburger Strings are there?

The first line is an integer T(T<=100).
Each case has an integer N(N<=100) in the first line.
Then N positive integers(<=20) follow, each corresponds a kind of color.
1 for red, 2 for yellow, and so on.

For each case output a single integer, indicating the number of Hamburger Strings are served.

3
1
1
2
2 2
10
1 2 3 4 3 1 2 4 1 5

0
1
2

计算机学院大学生程序设计竞赛（2014’11）