4 min read
Circular Array Loop: Cycles With Direction Constraints
Cycle detection with direction rules and path invalidation. Python solution and complexity analysis for the fast and slow pointers interview pattern.
Tag
Fast Slow Pointers
Articles tagged Fast Slow Pointers on The Augmented Dev.
11 articles
3 min read
Delete the Middle Node of a Linked List in One Pass
One-pass middle deletion — track the node before the midpoint. Python solution and complexity analysis for the fast and slow pointers interview pattern.
3 min read
Find the Duplicate Number as a Hidden Linked List Cycle
No mutation, O(1) space — the array is secretly a cyclic list. Python solution and complexity analysis for the fast and slow pointers interview pattern.
3 min read
Happy Number: Cycle Detection Without a Linked List
Floyd's algorithm on an implicit sequence — no nodes required. Python solution and complexity analysis for the fast and slow pointers interview pattern.
3 min read
Intersection of Two Linked Lists: The Pointer Switching Proof
Find where two lists merge by switching heads at the ends. Python solution and complexity analysis for the fast and slow pointers interview pattern.
3 min read
Linked List Cycle Detection With Floyd's Tortoise and Hare
Detect a cycle in O(1) space and argue why the pointers must meet. Python solution and complexity analysis for the fast and slow pointers interview pattern.
3 min read
Linked List Cycle II: Finding the Cycle Entry Point
Return the node where the cycle starts — and prove the reset trick. Python solution and complexity analysis for the fast and slow pointers interview pattern.
3 min read
Middle of the Linked List in One Pass
Find the midpoint without counting — the half-speed invariant. Python solution and complexity analysis for the fast and slow pointers interview pattern.
3 min read
Palindrome Linked List in O(1) Space: Split, Reverse, Compare
Palindrome check via midpoint split and half reversal. Python solution and complexity analysis for the fast and slow pointers interview pattern.
3 min read
Remove Nth Node From End With a Fixed Gap Walk
Delete the n-th from the end in one pass with a dummy head. Python solution and complexity analysis for the fast and slow pointers interview pattern.
3 min read
Reorder List: Three Linked List Primitives in One Question
L0-Ln-L1-Ln-1 interleaving via split, reverse, and merge. Python solution and complexity analysis for the fast and slow pointers interview pattern.