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Left View of a Binary Tree

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Left View of a Binary Tree

Meera only reaches for Left View of a Binary Tree when folder on disk has to stay correct in a file explorer.

Keep Left View of a Binary Tree small. Meera should finish folder on disk in a few lines, not a 40-line dump.

Left View of a Binary Tree exists so Meera can keep folder on disk correct in a file explorer.

Meera ships Left View of a Binary Tree in a file explorer. That is the use case worth saying.

Don’t do this with Left View of a Binary Tree: unbalanced BST becoming a list. Interviewers spot it in ten seconds.

Left View of a Binary Tree is not a lonely heading. Meera ties it to folder on disk.

Viva for Left View of a Binary Tree — what it is → left < root < right → the mistake (unbalanced BST becoming a list).

Exam tip

Board: folder on disk. Dry-run Left View of a Binary Tree. Name the trap: unbalanced BST becoming a list.

Example

class Node:
    def __init__(self, val, left=None, right=None):
        self.val, self.left, self.right = val, left, right

def inorder(n):
    if not n:
        return []
    return inorder(n.left) + [n.val] + inorder(n.right)

root = Node(2, Node(1), Node(3))
print(inorder(root))

Left View of a Binary Tree — inorder walks left → node → right (sorted order for a BST).

Short notes

DefLeft View of a Binary Tree — Meera uses it for folder on disk in a file explorer.
RuleLeft View of a Binary Tree → left < root < right.
RememberLeft View of a Binary Tree + time vs memory (a file explorer).
UseLeft View of a Binary Tree in a file explorer (folder on disk).
TrapLeft View of a Binary Tree — unbalanced BST becoming a list.
ExLeft View of a Binary Tree → folder on disk.

class Node: def __init__(self, val, left=None, right=None): self.val, self.left, self.right = val, left, right def inorder(n): if not n: return [] return inorder(n.left) + [n.val] + inorder(n.right) root = Node(2, Node(1), Node(3)) print(inorder(root))

Left View of a Binary Tree

Example

Short notes

Questions

Left View of a Binary Tree

Example

Short notes

Questions