How to Find the Left View of a Binary Tree Using BFS

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The left view of a binary tree consists of the first node visible at each level when the tree is observed from the left side. This can be solved efficiently using level-order traversal, also known as BFS, which processes nodes level by level from left to right. At each level, only the first node encountered is recorded as part of the left view. The approach uses a queue to push the root, then iterates through each level by tracking its size and capturing the node at index zero. Both the time and space complexity of this solution are O(N), where N is the total number of nodes in the tree.

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