End-Balanced Subarrays

You are given an array $a$ of $n$ integers. A sub-array $\[a\_l, a\_{l+1}, \cdots a\_r]$ is considered end-balanced if $l\<r$ and $a\_l + a\_r = a\_{l+1} + ... + a\_{r-1}$.

For example, the subarrays $\[4, 9, 5]$, $\[-1, 3, 5, 9]$, and $\[0, 0]$ are considered end-balanced, and the subarrays $\[0]$, $\[-2, -3, -5]$, and $\[1, 1]$ are not.

How many subarrays of $a$ are end-balanced?

The first line of the input contains a single integer $t$ ($1 \le t \le 10^4$) --- the number of test cases. The description of the test cases follows.

The first line of each test case contains a single integer $n$ ($1 \le n \le 2\cdot 10^5$) --- the size of the array $a$.

The second line of each test case contains $n$ integers $a\_1, a\_2 \cdots a\_n$ ($-10^9 \le a\_i \le 10^9$) --- the elements of the array $a$.

It is guaranteed that the sum of $n$ over all test cases does not exceed $2\cdot 10^5$.

For each test case, print a single integer --- the number of end-balanced subarrays of $a$.

The end-balanced subarrays in the first test case are:

• $\[a\_1, a\_2, a\_3, a\_4] = \[1, 2, 3, 4]$
• $\[a\_2, a\_3, a\_4, a\_5] = \[2, 3, 4, 5]$

The end-balanced subarrays in the second test case are:

• $\[a\_1, a\_2] = \[0, 0]$
• $\[a\_2, a\_3] = \[0, 0]$
• $\[a\_1, a\_2, a\_3] = \[0, 0, 0]$

The end-balanced subarrays in the third test case are:

• $\[a\_2, a\_3] = \[5, -5]$
• $\[a\_1, a\_2, a\_3, a\_4] = \[-10, 5, -5, 10]$