LeetCode Çözümlerİ – 141. Linked List Cycle

LeetCode içerisinde bulunan “Linked List Cycle” sorusunun açıklaması ve çözümü. Bu soruda head’i verilen bir linked list’in, içerisinde döngüsel bir yapı olup olmadığı soruluyor. Sorunun çözümü biraz karmaşık gelebilir bazı arkadaşlar için, o yüzden görseller ile de anlatmaya çalıştım, umarım anlaşılabilmişimdir.

➡️ Problem açıklaması:

There is a cycle in a linked list if there is some node in the list that can be reached again by continuously following the next pointer. Internally, pos is used to denote the index of the node that tail’s next pointer is connected to. Note that pos is not passed as a parameter.

Return true if there is a cycle in the linked list. Otherwise, return false.

Example 1:

Input: head = [3,2,0,-4], pos = 1

Output: true

Explanation: There is a cycle in the linked list, where the tail connects to the 1st node (0-indexed).

Example 2:

Input: head = [1,2], pos = 0

Output: true

Explanation: There is a cycle in the linked list, where the tail connects to the 0th node.

Example 3:

Input: head = , pos = -1

Output: false

Explanation: There is no cycle in the linked list.

Constraints:

The number of the nodes in the list is in the range [0, 104].

-105 lessEqual Node.val lessEqual 105

pos is -1 or a valid index in the linked-list.

Follow up: Can you solve it using O(1) (i.e. constant) memory?