zoukankan      html  css  js  c++  java
  • 【leetcode】654. Maximum Binary Tree

    题目如下:

    Given an integer array with no duplicates. A maximum tree building on this array is defined as follow:

    1. The root is the maximum number in the array.
    2. The left subtree is the maximum tree constructed from left part subarray divided by the maximum number.
    3. The right subtree is the maximum tree constructed from right part subarray divided by the maximum number.

    Construct the maximum tree by the given array and output the root node of this tree.

    Example 1:

    Input: [3,2,1,6,0,5]
    Output: return the tree root node representing the following tree:
    
          6
        /   
       3     5
            / 
         2  0   
           
            1
    

    Note:

    1. The size of the given array will be in the range [1,1000].

    解题思路:题目不难,从72%通过率就能看出来。方法是找出数组的最大值并作为根节点,然后把数组以最大值为界分成左右两部分;之后再对左右两部分分别递归,直到数组被分割完成为止。

    代码如下:

    # Definition for a binary tree node.
    # class TreeNode(object):
    #     def __init__(self, x):
    #         self.val = x
    #         self.left = None
    #         self.right = None
    
    class Solution(object):
        def build(self,node,nums):
            v = max(nums)
            inx = nums.index(v)
            node.val = v
    
            ll = nums[:inx]
            rl = nums[inx+1:]
            if len(ll) > 0:
                left = TreeNode(None)
                node.left = left
                self.build(left,ll)
            if len(rl) > 0:
                right = TreeNode(None)
                node.right = right
                self.build(right,rl)
    
        def constructMaximumBinaryTree(self, nums):
            """
            :type nums: List[int]
            :rtype: TreeNode
            """
            root = TreeNode(None)
            self.build(root,nums)
            return root
            
  • 相关阅读:
    k8s二进制安装
    jenkins
    Deploy Apollo on Kubernetes
    Apollo配置中心搭建常见报错
    Apollo配置中心搭建过程
    使用CephRBD为Kubernetes提供StorageClass
    Ceph基础命令总结
    Ceph分布式存储系统搭建
    zabbix入门之配置邮件告警
    zabbix入门之定义触发器
  • 原文地址:https://www.cnblogs.com/seyjs/p/10428443.html
Copyright © 2011-2022 走看看