104:Maximum Depth of Binary Tree【樹】【DFS】

題目鏈接：click~

/*題意：求二叉樹的深度*/
class Solution {
public:
    int maxDepth(TreeNode *root) {
        if(root == NULL) return 0;
        return max(maxDepth(root->left), maxDepth(root->right)) + 1;
    }
};