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50 lines
1.9 KiB
HTML
50 lines
1.9 KiB
HTML
<p>Given a root node reference of a BST and a key, delete the node with the given key in the BST. Return the root node reference (possibly updated) of the BST.</p>
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<p>Basically, the deletion can be divided into two stages:</p>
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<ol>
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<li>Search for a node to remove.</li>
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<li>If the node is found, delete the node.</li>
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</ol>
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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/2020/09/04/del_node_1.jpg" style="width: 800px; height: 214px;" />
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<pre>
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<strong>Input:</strong> root = [5,3,6,2,4,null,7], key = 3
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<strong>Output:</strong> [5,4,6,2,null,null,7]
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<strong>Explanation:</strong> Given key to delete is 3. So we find the node with value 3 and delete it.
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One valid answer is [5,4,6,2,null,null,7], shown in the above BST.
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Please notice that another valid answer is [5,2,6,null,4,null,7] and it's also accepted.
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<img alt="" src="https://assets.leetcode.com/uploads/2020/09/04/del_node_supp.jpg" style="width: 350px; height: 255px;" />
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</pre>
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<p><strong>Example 2:</strong></p>
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<pre>
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<strong>Input:</strong> root = [5,3,6,2,4,null,7], key = 0
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<strong>Output:</strong> [5,3,6,2,4,null,7]
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<strong>Explanation:</strong> The tree does not contain a node with value = 0.
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</pre>
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<p><strong>Example 3:</strong></p>
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<pre>
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<strong>Input:</strong> root = [], key = 0
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<strong>Output:</strong> []
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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>[0, 10<sup>4</sup>]</code>.</li>
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<li><code>-10<sup>5</sup> <= Node.val <= 10<sup>5</sup></code></li>
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<li>Each node has a <strong>unique</strong> value.</li>
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<li><code>root</code> is a valid binary search tree.</li>
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<li><code>-10<sup>5</sup> <= key <= 10<sup>5</sup></code></li>
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</ul>
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<p> </p>
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<p><strong>Follow up:</strong> Could you solve it with time complexity <code>O(height of tree)</code>?</p>
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