Package g0301_0400.s0382_linked_list_random_node

Class Solution

java.lang.Object
g0301_0400.s0382_linked_list_random_node.Solution
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:** ![](https://assets.leetcode.com/uploads/2021/03/16/getrand-linked-list.jpg) **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?

  • Constructor Details

    • Solution

      public Solution(ListNode head)

  • Method Details

    • getRandom

      public int getRandom()