Find Starting Point of Loop in Linked List
Medium Problems of Singly Linked List DSA practice problem on Onlearn.
Difficulty: medium.
Topics: Detecting and Finding the Starting Point of a Cycle in a Linked List, Linked List, Node, Pointer, Data Structures, Map, Hash Tables, Two Pointers, Time Complexity, Space Complexity, Big O Notation, Brute Force, Optimization, Loops, linked list traversal, mathematical proof, pointer operations, hash map, cycle detection, time complexity analysis, two pointer technique, Cycle Detection (Hashing), Mathematical Operations.
Find the Starting Point of a Cycle in a Linked List Problem Statement Given the head of a singly linked list that may contain a cycle, return the starting point of that cycle. If there is no cycle in the linked list, return null. Input Specification The input will be the head of a singly linked list. Output Specification Return the Node object representing the starting point of the cycle. If no cycle exists, return null. Examples Example 1: Input: LL: 1 2 3 4 5 (where 5 points back to 3) Output: 3 Explanation: This linked list contains a loop of size 3 starting at the node with value 3. Example 2: Input: LL: 1 2 3 4 9 9 Output: NULL Explanation: This linked list does not contain a loop, hence has no starting point.