 # How to implement this in Java / Python ? Any hint on how to approach

Happy Trees
You’re given a balanced bracket expression. In the forest representation of it, find the number of trees which are happy. A happy tree is a tree in which every vertex other than the leaves has the same number of children. A tree with just one vertex would also be considered happy.

Input Format
First line of input consists of an integer t denoting the number of test cases. First line of each test case consists of an integer n denoting the length of the expression. Second line consists of the bracket expression.

Output Format
For each test case, find the number of trees which are happy.

Constraints
1 <= t <= 1000

n = 2 * m where 1 <= m <= 1000

Sample Input
4
12
[[[][]][[]]]
20
[[[][][]][][[][][]]]
14
[[]][[][[]]][]
28
[[[][]][[][]]][[][]][[[[]]]]
Sample Output
0
1
2
3

Explanation
The expression [[[][]][[]]] has the following representation

[]
├── []
│ ├── []
│ └── []
└── []
└── []
There is only one tree. Root and second child of root has two children each. First child of root has only one child. It’s not happy.

The expression [[[][][]][][[][][]]] has the following representation

[]
├── []
│ ├── []
│ ├── []
│ └── []
├── []
└── []
├── []
├── []
└── []
There is only one tree. All non-leaf vertices have exactly 3 children. Tree is happy.

The expression [[]][[][[]]][] has the following representation

[]
└── []
[]
├── []
└── []
└── []
[]
There are three trees. Only two of them are happy.

The expression [[[][]][[][]]][[][]][[[[]]]] has the following representation

[]
├── []
│ ├── []
│ └── []
└── []
├── []
└── []
[]
├── []
└── []
[]
└── []
└── []
└── []
The number of happy trees is 3.

were you able to solve?