[LeetCode] Maximum Depth of Binary Tree 二叉树的最大深度

 

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.

 

求二叉树的最大深度问题用到深度优先搜索DFS，递归的完美应用，跟求二叉树的最小深度问题原理相同。代码如下：

 

/**
 * Definition for binary tree
 * 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 == NULL) return 0;
        if (root->left == NULL && root->right == NULL) return 1;
        if (root->left == NULL) return 1 + maxDepth(root->right);
        else if (root->right == NULL) return 1 + maxDepth(root->left);
        else return 1 + max(maxDepth(root->left), maxDepth(root->right));
    }
};

 

求二叉树的最小深度可以参见我的博文：

http://www.cnblogs.com/grandyang/p/4042168.html

 

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