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29 lines
1.2 KiB
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29 lines
1.2 KiB
HTML
<p>Given the <code>root</code> of a binary search tree, and an integer <code>k</code>, return <em>the</em> <code>k<sup>th</sup></code> <em>smallest value (<strong>1-indexed</strong>) of all the values of the nodes in the tree</em>.</p>
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<p> </p>
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<p><strong>Example 1:</strong></p>
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<img alt="" src="https://assets.leetcode.com/uploads/2021/01/28/kthtree1.jpg" style="width: 212px; height: 301px;" />
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<pre>
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<strong>Input:</strong> root = [3,1,4,null,2], k = 1
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<strong>Output:</strong> 1
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</pre>
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<p><strong>Example 2:</strong></p>
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<img alt="" src="https://assets.leetcode.com/uploads/2021/01/28/kthtree2.jpg" style="width: 382px; height: 302px;" />
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<pre>
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<strong>Input:</strong> root = [5,3,6,2,4,null,null,1], k = 3
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<strong>Output:</strong> 3
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</pre>
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<p> </p>
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<p><strong>Constraints:</strong></p>
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<ul>
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<li>The number of nodes in the tree is <code>n</code>.</li>
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<li><code>1 <= k <= n <= 10<sup>4</sup></code></li>
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<li><code>0 <= Node.val <= 10<sup>4</sup></code></li>
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</ul>
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<p> </p>
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<p><strong>Follow up:</strong> If the BST is modified often (i.e., we can do insert and delete operations) and you need to find the kth smallest frequently, how would you optimize?</p>
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