LeetCode_Maximum Depth of Binary Tree

一.題目

Maximum Depth of Binary Tree

  Total Accepted: 70693 Total Submissions: 156776My Submissions

Given a binary tree, find its maximum depth.

The maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node.

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二.解題技巧

    這道題和Minimum Depth of Binary Tree類似，只不過這個是求最大深度的，解法也和Minimum Depth of Binary Tree一樣，都是對二叉樹進行遞歸，然後將子樹的最大深度進行返回，最終得到這個樹的最大深度。

    這個方法的時間複雜度爲O(n),空間複雜都爲O(logn)。

三.實現代碼

#include <iostream>

/**
* Definition for a binary tree node.
* struct TreeNode {
*     int val;
*     TreeNode *left;
*     TreeNode *right;
*     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/


struct TreeNode
{
    int val;
    TreeNode *left;
    TreeNode *right;
    TreeNode(int x) : val(x), left(NULL), right(NULL) {}
};

class Solution
{
public:
    int maxDepth(TreeNode* root)
    {
        if (!root)
        {
            return 0;
        }

        int Result = 1;
        int Left = maxDepth(root->left);
        int Right = maxDepth(root->right);

        if (Left * Right)
        {
            Result += Left < Right? Right : Left;
        }
        else
        {
            Result += Right + Left;
        }

        return Result;
    }
};

四.體會

    這是一道類似的題，只是改改代碼就可以實現了。

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