Determine the Left View of a Binary Tree

You are given a binary tree of integers. Your task is to determine the left view of the binary tree. The left view consists of nodes that are visible when the tree is viewed from the left side.

Example:

Input:

T = 1
Binary Tree Level Order Input: 1 2 3 4 -1 5 6 -1 7 -1 -1 -1 -1 -1 -1

Output:

1 2 4 7

Explanation:

The left view of the binary tree is 1, 2, 4, 7 as shown in the image below:

Constraints:

1

Question

Determine the Left View of a Binary Tree

You are given a binary tree of integers. Your task is to determine the left view of the binary tree. The left view consists of nodes that are visible when the tree is viewed from the left side.

Example:

Input:

T = 1
Binary Tree Level Order Input: 1 2 3 4 -1 5 6 -1 7 -1 -1 -1 -1 -1 -1

Output:

1 2 4 7

Explanation:

The left view of the binary tree is 1, 2, 4, 7 as shown in the image below:

example image

Constraints:

1 <= T <= 100
0 <= N <= 3000
1 <= data <= 10⁵ and data ≠ -1

Note:

You do not need to handle any input/output operations; just implement the function to return the required result.

Accepted Answer

The task is to determine the left view of a binary tree, which consists of nodes visible when viewed from the left side.

Traverse the binary tree level by level from left to right, keeping track of the first node encountered at each level.
Use a queue to perform level order traversal of the binary tree.
Store the leftmost node at each level in the result array.
Return the result array containing the left view of the binary tree.