382. Linked List Random Node
Medium
30 Points
Linked List
Math
Reservoir Sampling
Randomized
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:
Examples
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 <= 104At most 104 calls will be made to getRandom.
382. Linked List Random Node
Medium
30 Points
Linked List
Math
Reservoir Sampling
Randomized
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:
Examples
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 <= 104At most 104 calls will be made to getRandom.