[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.
問題解決の考え方:
この問題は二叉木の高さを求めるだけだ.2行のコードを解くだけでいい.

/**
 * 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) {
        if(root==NULL){
            return 0;
        }
        return max(maxDepth(root->left), maxDepth(root->right)) + 1;
    }
};