DSA · Theory

The Great Tree-List Recursion Problem

Theory

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The Great Tree-List Recursion Problem (alt) is a DSA idea you prove with folder on disk, not with a slogan.

The Great Tree-List Recursion Problem (alt) order: meaning → left < root < right → one limit. Dumping ten features helps nobody.

Without The Great Tree-List Recursion Problem (alt), a file explorer gets messy and folder on disk is hard to trust.

Dev ships The Great Tree-List Recursion Problem (alt) in a file explorer. That is the use case worth saying.

If folder on disk breaks under The Great Tree-List Recursion Problem (alt), check unbalanced BST becoming a list first.

After The Great Tree-List Recursion Problem (alt), Dev should still remember unbalanced BST becoming a list.

Close The Great Tree-List Recursion Problem (alt) with: “If I skip it, folder on disk goes wrong like this: unbalanced BST becoming a list.”

Exam tip

Board: folder on disk. Dry-run The Great Tree-List Recursion Problem (alt). Name the trap: unbalanced BST becoming a list.

def factorial(n):
    if n <= 1:
        return 1
    return n * factorial(n - 1)

print(factorial(5))

The Great Tree-List Recursion Problem (alt) — recursion solves a problem using smaller instances of itself + a base case.

DefThe Great Tree-List Recursion Problem (alt) — Dev uses it for folder on disk in a file explorer.
RuleThe Great Tree-List Recursion Problem (alt) → left < root < right.
RememberThe Great Tree-List Recursion Problem (alt) + Big-O (a file explorer).
UseThe Great Tree-List Recursion Problem (alt) in a file explorer (folder on disk).
TrapThe Great Tree-List Recursion Problem (alt) — unbalanced BST becoming a list.
ExThe Great Tree-List Recursion Problem (alt) → folder on disk.