Test for an Exact Descendant Subtree Match

### Problem Return whether some node of root, together with all its descendants, forms a tree identical to subRoot in both shape and values. The whole root tree is also a candidate subtree. Both parameters are TreeNode pointers. ```cpp class Solution { public: bool isSubtree(TreeNode* root, TreeNode* subRoot); }; ``` ### Examples **Example 1:** ```text root = [8,4,11,2,6], subRoot = [4,2,6] Output: true Explanation: The subtree beginning at node 4 matches exactly. ``` **Example 2:** ```text root = [8,4,11,2,6], subRoot = [4,2] Output: false Explanation: The extra descendant 6 prevents an exact match. ``` ### Constraints - The main tree has 1..2000 nodes; the proposed subtree has 1..1000. In either tree, values lie in -10000..10000. ### Clarifying Questions Compare full structure, including absent children, and allow the match to start at the root itself. ```hint Read the boundary condition How can an equality check distinguish a missing child from an extra descendant? ``` ### Contract considerations Compare full structure, including absent children, and allow the match to start at the root itself.