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44 lines
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44 lines
2.0 KiB
HTML
<p>You are given an integer array <code>nums</code> with no duplicates. A <strong>maximum binary tree</strong> can be built recursively from <code>nums</code> using the following algorithm:</p>
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<ol>
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<li>Create a root node whose value is the maximum value in <code>nums</code>.</li>
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<li>Recursively build the left subtree on the <strong>subarray prefix</strong> to the <strong>left</strong> of the maximum value.</li>
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<li>Recursively build the right subtree on the <strong>subarray suffix</strong> to the <strong>right</strong> of the maximum value.</li>
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</ol>
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<p>Return <em>the <strong>maximum binary tree</strong> built from </em><code>nums</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/2020/12/24/tree1.jpg" style="width: 302px; height: 421px;" />
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<pre>
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<strong>Input:</strong> nums = [3,2,1,6,0,5]
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<strong>Output:</strong> [6,3,5,null,2,0,null,null,1]
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<strong>Explanation:</strong> The recursive calls are as follow:
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- The largest value in [3,2,1,6,0,5] is 6. Left prefix is [3,2,1] and right suffix is [0,5].
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- The largest value in [3,2,1] is 3. Left prefix is [] and right suffix is [2,1].
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- Empty array, so no child.
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- The largest value in [2,1] is 2. Left prefix is [] and right suffix is [1].
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- Empty array, so no child.
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- Only one element, so child is a node with value 1.
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- The largest value in [0,5] is 5. Left prefix is [0] and right suffix is [].
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- Only one element, so child is a node with value 0.
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- Empty array, so no child.
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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/2020/12/24/tree2.jpg" style="width: 182px; height: 301px;" />
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<pre>
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<strong>Input:</strong> nums = [3,2,1]
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<strong>Output:</strong> [3,null,2,null,1]
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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><code>1 <= nums.length <= 1000</code></li>
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<li><code>0 <= nums[i] <= 1000</code></li>
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<li>All integers in <code>nums</code> are <strong>unique</strong>.</li>
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</ul>
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