Leetcode:Maximum Depth of Binary Tree

Maximum Depth of Binary Tree

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.

解题思路：

课本上的做法，采用递归的方法，比较左右子树的的高度，返回较高的子树并加1（根节点）

/**
 * 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;
        int leftlength = maxDepth(root->left);
        int rightlength = maxDepth(root->right);
        if(leftlength > rightlength)
            return leftlength+1;
        else
            return rightlength+1;
    }
};