This problem is about constructing a Binary Search Tree (BST) from an array of unique elements and printing the Level Order of the tree from bottom to top.

Here are the steps to solve this problem:

1. Parse the input: The first line of input contains T - the number of test cases. Each test case is followed by two lines. The first line contains N - the number of nodes in the BST. The second line contains N unique integers - the values of the nodes.

2. Construct the BST: For each test case, construct a BST using the given array of unique elements. A BST is a tree in which for each node, all elements in its left subtree are less than the node, and all elements in its right subtree are greater than the node.

3. Traverse the BST in Level Order from bottom to top: This can be done by using a queue and a stack. First, perform a regular level order traversal (top to bottom) and push each level into a stack. Then, pop each level from the stack and print it. This will give the level order from bottom to top.

4. Print the output: For each test case, print the bottom-up Level Order of the Binary Search Tree, separating each level by a newline. Separate the output of different test cases with an extra newline.

Constraints:
- 1

Question

This problem is about constructing a Binary Search Tree (BST) from an array of unique elements and printing the Level Order of the tree from bottom to top.

Here are the steps to solve this problem:

1. Parse the input: The first line of input contains T - the number of test cases. Each test case is followed by two lines. The first line contains N - the number of nodes in the BST. The second line contains N unique integers - the values of the nodes.

2. Construct the BST: For each test case, construct a BST using the given array of unique elements. A BST is a tree in which for each node, all elements in its left subtree are less than the node, and all elements in its right subtree are greater than the node.

3. Traverse the BST in Level Order from bottom to top: This can be done by using a queue and a stack. First, perform a regular level order traversal (top to bottom) and push each level into a stack. Then, pop each level from the stack and print it. This will give the level order from bottom to top.

4. Print the output: For each test case, print the bottom-up Level Order of the Binary Search Tree, separating each level by a newline. Separate the output of different test cases with an extra newline.

Constraints:
- 1 <= T <= 1000
- 1 <= N <= 1000
- 0 <= ar[i] <= 10000

Example:
Input:
3
5
1 2 3 4 5
5
3 2 4 1 5
7
4 5 15 0 1 7 17

Output:
5
4 3
2 1

5
2 1
4

17
7
15
1 0
5 4

Knowee AI · Accepted Answer