Class Solution
java.lang.Object
g0301_0400.s0382_linked_list_random_node.Solution
382 - Linked List Random Node.<p>Medium</p>
<p>Given a singly linked list, return a random node’s value from the linked list. Each node must have the <strong>same probability</strong> of being chosen.</p>
<p>Implement the <code>Solution</code> class:</p>
<ul>
<li><code>Solution(ListNode head)</code> Initializes the object with the integer array nums.</li>
<li><code>int getRandom()</code> Chooses a node randomly from the list and returns its value. All the nodes of the list should be equally likely to be choosen.</li>
</ul>
<p><strong>Example 1:</strong></p>
<p><img src="https://assets.leetcode.com/uploads/2021/03/16/getrand-linked-list.jpg" alt="" /></p>
<p><strong>Input</strong></p>
<pre><code> ["Solution", "getRandom", "getRandom", "getRandom", "getRandom", "getRandom"]
[[[1, 2, 3]], [], [], [], [], []]
</code></pre>
<p><strong>Output:</strong></p>
<pre><code> [null, 1, 3, 2, 2, 3]
</code></pre>
<p><strong>Explanation:</strong></p>
<pre><code> 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.
</code></pre>
<p><strong>Constraints:</strong></p>
<ul>
<li>The number of nodes in the linked list will be in the range <code>[1, 10<sup>4</sup>]</code>.</li>
<li><code>-10<sup>4</sup> <= Node.val <= 10<sup>4</sup></code></li>
<li>At most <code>10<sup>4</sup></code> calls will be made to <code>getRandom</code>.</li>
</ul>
<p><strong>Follow up:</strong></p>
<ul>
<li>What if the linked list is extremely large and its length is unknown to you?</li>
<li>Could you solve this efficiently without using extra space?</li>
</ul>
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Constructor Summary
Constructors -
Method Summary
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Constructor Details
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Solution
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Method Details
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getRandom
public int getRandom()
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