• Home
• com.github.javadev
• leetcode-in-java
• 1.38
• source code
• readme.md

×

Project download

Many resources are needed to download a project. Please understand that we have to compensate our server costs. Thank you in advance.
Project price only 1 $

You can buy this project and download/modify it how often you want.

g0601_0700.s0654_maximum_binary_tree.readme.md Maven / Gradle / Ivy

654\. Maximum Binary Tree

Medium

You are given an integer array `nums` with no duplicates. A **maximum binary tree** can be built recursively from `nums` using the following algorithm:

1.  Create a root node whose value is the maximum value in `nums`.
2.  Recursively build the left subtree on the **subarray prefix** to the **left** of the maximum value.
3.  Recursively build the right subtree on the **subarray suffix** to the **right** of the maximum value.

Return _the **maximum binary tree** built from_ `nums`.

**Example 1:**

![](https://assets.leetcode.com/uploads/2020/12/24/tree1.jpg)

**Input:** nums = [3,2,1,6,0,5]

**Output:** [6,3,5,null,2,0,null,null,1]

**Explanation:** The recursive calls are as follow: 

- The largest value in [3,2,1,6,0,5] is 6. Left prefix is [3,2,1] and right suffix is [0,5].

    - The largest value in [3,2,1] is 3. Left prefix is [] and right suffix is [2,1]. 
  
        - Empty array, so no child. 
      
        - The largest value in [2,1] is 2. Left prefix is [] and right suffix is [1]. 
      
            - Empty array, so no child. 
          
            - Only one element, so child is a node with value 1.
      
    - The largest value in [0,5] is 5. Left prefix is [0] and right suffix is []. 
  
        - Only one element, so child is a node with value 0. 
      
        - Empty array, so no child.

**Example 2:**

![](https://assets.leetcode.com/uploads/2020/12/24/tree2.jpg)

**Input:** nums = [3,2,1]

**Output:** [3,null,2,null,1]

**Constraints:**

*   `1 <= nums.length <= 1000`
*   `0 <= nums[i] <= 1000`
*   All integers in `nums` are **unique**.