#P1985C. Good Prefixes
Good Prefixes
No submission language available for this problem.
Description
Alex thinks some array is good if there exists some element that can be represented as the sum of all other elements (the sum of all other elements is if there are no other elements). For example, the array is good since . Furthermore, the array is also good. However, the arrays and are not good.
Alex has an array . Help him count the number of good non-empty prefixes of the array . In other words, count the number of integers () such that the length prefix (i.e. ) is good.
The first line of the input contains a single integer () — the number of test cases.
The first line of each test case contains a single integer () — the number of elements in the array.
The second line of each test case contains integers () — the elements of the array.
It is guaranteed that the sum of over all test cases does not exceed .
For each test case, output a single integer — the number of good non-empty prefixes of the array .
Input
The first line of the input contains a single integer () — the number of test cases.
The first line of each test case contains a single integer () — the number of elements in the array.
The second line of each test case contains integers () — the elements of the array.
It is guaranteed that the sum of over all test cases does not exceed .
Output
For each test case, output a single integer — the number of good non-empty prefixes of the array .
Note
In the fourth test case, the array has five prefixes:
- prefix is a good array, as mentioned in the statement;
- prefix is not a good array, since ;
- prefix is not a good array, since , and ;
- prefix is a good array, since ;
- prefix is a good array, since .
As you can see, three of them are good, so the answer is .