Measure Binary-Tree Width Including Internal Null Gaps

### Problem Return the greatest width among levels of root. A level's width counts complete-tree slots from its leftmost nonnull node through its rightmost nonnull node, including missing slots between them. The result fits signed 32-bit int. ```cpp class Solution { public: int widthOfBinaryTree(TreeNode* root); }; ``` ### Examples **Example 1:** ```text root = [8,4,12,2,null,null,14] Output: 4 Explanation: The last level spans slots [2,null,null,14]. ``` **Example 2:** ```text root = [5,null,7,null,9] Output: 1 Explanation: A single node at each level has width one. ``` ### Constraints - Tree size: 1..3000 nodes, with values in -100..100. The final width has the signed-32-bit fit promise stated above. ### Clarifying Questions Include null slots between endpoints and prevent index overflow without changing relative positions. ```hint Read the boundary condition Can subtracting the same level offset preserve every width calculation? ``` ### Contract considerations Include null slots between endpoints and prevent index overflow without changing relative positions.