DSA · Theory

Find a pair with given sum in a Balanced BST

Theory

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Find a pair with given sum in a Balanced BST

If you can teach Find a pair with given sum in a Balanced BST using folder on disk, you know it. If you only know the heading, you don’t.

For Find a pair with given sum in a Balanced BST, Big-O is in play. Don’t blame it until you have traced folder on disk.

Skip Find a pair with given sum in a Balanced BST and unbalanced BST becoming a list shows up in a file explorer.

Asha ships Find a pair with given sum in a Balanced BST in a file explorer. That is the use case worth saying.

Find a pair with given sum in a Balanced BST miss: unbalanced BST becoming a list. Fix it before you talk about advanced DSA.

After Find a pair with given sum in a Balanced BST, Asha should still remember unbalanced BST becoming a list.

One breath for Find a pair with given sum in a Balanced BST, then folder on disk, then unbalanced BST becoming a list. Sit down.

Diagram

Exam tip

For Find a pair with given sum in a Balanced BST: definition + a file explorer + one failure.

Example

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

def insert(root, val):
    if root is None:
        return Node(val)
    if val < root.val:
        root.left = insert(root.left, val)
    elif val > root.val:
        root.right = insert(root.right, val)
    return root

root = None
for v in [5, 2, 7, 1]:
    root = insert(root, v)
print(root.val, root.left.val, root.right.val)

Find a pair with given sum in a Balanced BST — bST invariant: left < node < right — enables log-time search when balanced.

Short notes

DefFind a pair with given sum in a Balanced BST — Asha uses it for folder on disk in a file explorer.
RuleFind a pair with given sum in a Balanced BST → left < root < right.
RememberFind a pair with given sum in a Balanced BST + Big-O (a file explorer).
UseFind a pair with given sum in a Balanced BST in a file explorer (folder on disk).
TrapFind a pair with given sum in a Balanced BST — unbalanced BST becoming a list.
ExFind a pair with given sum in a Balanced BST → folder on disk.

class Node: def __init__(self, val): self.val = val self.left = None self.right = None def insert(root, val): if root is None: return Node(val) if val < root.val: root.left = insert(root.left, val) elif val > root.val: root.right = insert(root.right, val) return root root = None for v in [5, 2, 7, 1]: root = insert(root, v) print(root.val, root.left.val, root.right.val)

Find a pair with given sum in a Balanced BST

Example

Short notes

Questions

Find a pair with given sum in a Balanced BST

Example

Short notes

Questions