Level Order BST Serialization

Implement a function that serializes a binary search tree into a level-order formatted string. Each level of the tree should be represented by square brackets and levels should be separated by commas. The input format consists of several lines: the first line contains an integer n (the number of nodes), followed by n lines which contain the values for each node. Print the serialized level-order representation. Example input/output is shown below. Input: 5 10 5 15 3 7 Output: [10], [5, 15], [3, 7]