public class Solution
extends Object
382 - Linked List Random Node\.
Medium
Given a singly linked list, return a random node's value from the linked list. Each node must have the **same probability** of being chosen.
Implement the `Solution` class:
* `Solution(ListNode head)` Initializes the object with the integer array nums.
* `int getRandom()` Chooses a node randomly from the list and returns its value. All the nodes of the list should be equally likely to be choosen.
**Example 1:**
**Input**
["Solution", "getRandom", "getRandom", "getRandom", "getRandom", "getRandom"]
[[[1, 2, 3]], [], [], [], [], []]
**Output:**
[null, 1, 3, 2, 2, 3]
**Explanation:**
Solution solution = new Solution([1, 2, 3]);
solution.getRandom(); // return 1
solution.getRandom(); // return 3
solution.getRandom(); // return 2
solution.getRandom(); // return 2
solution.getRandom(); // return 3
// getRandom() should return either 1, 2, or 3 randomly. Each element should have equal probability of returning.
**Constraints:**
* The number of nodes in the linked list will be in the range [1, 104].
* -104 <= Node.val <= 104
* At most 104 calls will be made to `getRandom`.
**Follow up:**
* What if the linked list is extremely large and its length is unknown to you?
* Could you solve this efficiently without using extra space?