【LeetCode】104. Maximum Depth of Binary Tree（C++）

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.

Note: A leaf is a node with no children.

Example:

Given binary tree [3,9,20,null,null,15,7],

    3
   / \
  9  20
    /  \
   15   7

return its depth = 3.

递归求二叉树的最大深度

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution {
public:
    int maxDepth(TreeNode* root) {
        int res=0,res1,res2;
        TreeNode *t;
        t=root;
        if(t!=NULL)
        {
            res++;
            res1=maxDepth(t->left);
            res2=maxDepth(t->right);
            if(res1>res2)
                res=res+res1;
            else
                res=res+res2;
        }
        return res;
    }
};