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.
What if the linked list is extremely large and its length is unknown to you? Could you solve this efficiently without using extra space?
// Init a singly linked list [1,2,3]. ListNode head = new ListNode(1); head.next = new ListNode(2); head.next.next = new ListNode(3); Solution solution = new Solution(head);
// getRandom() should return either 1, 2, or 3 randomly. Each element should have equal probability of returning. solution.getRandom();
- Random Pick Index (Medium)