Middle of the Linked List

Question

Given a non-empty, singly linked list with head node head, return the middle node of the linked list. If there are two middle nodes, return the second middle node.

Example 1

Input: 1->2->3->4->5
Output: Node 3

Solution

▭

all//Middle of the Linked List.py

# Definition for singly-linked list.
class ListNode:
    def __init__(self, x):
        self.val = x
        self.next = None

class Solution:
    def middleNode(self, head):
        slow = fast = head
        while fast and fast.next:
            slow = slow.next
            fast = fast.next.next
        return slow

▯

all//Middle of the Linked List.py

# Definition for singly-linked list.
class ListNode:
    def __init__(self, x):
        self.val = x
        self.next = None

class Solution:
    def middleNode(self, head):
        slow = fast = head
        while fast and fast.next:
            slow = slow.next
            fast = fast.next.next
        return slow