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27 lines
1.2 KiB
HTML
27 lines
1.2 KiB
HTML
<p>Given the <code>root</code> of a binary search tree and an integer <code>k</code>, return <code>true</code> <em>if there exist two elements in the BST such that their sum is equal to</em> <code>k</code>, <em>or</em> <code>false</code> <em>otherwise</em>.</p>
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<p> </p>
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<p><strong class="example">Example 1:</strong></p>
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<img alt="" src="https://assets.leetcode.com/uploads/2020/09/21/sum_tree_1.jpg" style="width: 400px; height: 229px;" />
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<pre>
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<strong>Input:</strong> root = [5,3,6,2,4,null,7], k = 9
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<strong>Output:</strong> true
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</pre>
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<p><strong class="example">Example 2:</strong></p>
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<img alt="" src="https://assets.leetcode.com/uploads/2020/09/21/sum_tree_2.jpg" style="width: 400px; height: 229px;" />
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<pre>
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<strong>Input:</strong> root = [5,3,6,2,4,null,7], k = 28
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<strong>Output:</strong> false
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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 in the range <code>[1, 10<sup>4</sup>]</code>.</li>
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<li><code>-10<sup>4</sup> <= Node.val <= 10<sup>4</sup></code></li>
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<li><code>root</code> is guaranteed to be a <strong>valid</strong> binary search tree.</li>
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<li><code>-10<sup>5</sup> <= k <= 10<sup>5</sup></code></li>
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</ul>
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