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55 lines
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55 lines
2.6 KiB
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<p>A <strong>maximum tree</strong> is a tree where every node has a value greater than any other value in its subtree.</p>
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<p>You are given the <code>root</code> of a maximum binary tree and an integer <code>val</code>.</p>
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<p>Just as in the <a href="https://leetcode.com/problems/maximum-binary-tree/" target="_blank">previous problem</a>, the given tree was constructed from a list <code>a</code> (<code>root = Construct(a)</code>) recursively with the following <code>Construct(a)</code> routine:</p>
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<ul>
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<li>If <code>a</code> is empty, return <code>null</code>.</li>
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<li>Otherwise, let <code>a[i]</code> be the largest element of <code>a</code>. Create a <code>root</code> node with the value <code>a[i]</code>.</li>
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<li>The left child of <code>root</code> will be <code>Construct([a[0], a[1], ..., a[i - 1]])</code>.</li>
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<li>The right child of <code>root</code> will be <code>Construct([a[i + 1], a[i + 2], ..., a[a.length - 1]])</code>.</li>
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<li>Return <code>root</code>.</li>
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</ul>
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<p>Note that we were not given <code>a</code> directly, only a root node <code>root = Construct(a)</code>.</p>
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<p>Suppose <code>b</code> is a copy of <code>a</code> with the value <code>val</code> appended to it. It is guaranteed that <code>b</code> has unique values.</p>
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<p>Return <code>Construct(b)</code>.</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/2021/08/09/maxtree1.JPG" style="width: 376px; height: 235px;" />
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<pre>
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<strong>Input:</strong> root = [4,1,3,null,null,2], val = 5
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<strong>Output:</strong> [5,4,null,1,3,null,null,2]
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<strong>Explanation:</strong> a = [1,4,2,3], b = [1,4,2,3,5]
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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/2021/08/09/maxtree21.JPG" style="width: 358px; height: 156px;" />
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<pre>
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<strong>Input:</strong> root = [5,2,4,null,1], val = 3
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<strong>Output:</strong> [5,2,4,null,1,null,3]
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<strong>Explanation:</strong> a = [2,1,5,4], b = [2,1,5,4,3]
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</pre>
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<p><strong>Example 3:</strong></p>
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<img alt="" src="https://assets.leetcode.com/uploads/2021/08/09/maxtree3.JPG" style="width: 404px; height: 180px;" />
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<pre>
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<strong>Input:</strong> root = [5,2,3,null,1], val = 4
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<strong>Output:</strong> [5,2,4,null,1,3]
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<strong>Explanation:</strong> a = [2,1,5,3], b = [2,1,5,3,4]
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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, 100]</code>.</li>
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<li><code>1 <= Node.val <= 100</code></li>
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<li>All the values of the tree are <strong>unique</strong>.</li>
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<li><code>1 <= val <= 100</code></li>
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</ul>
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