Given the root of a binary tree, return the leftmost value in the last row of the tree.
\n
Example 1:
\n![\"\"](\"https://assets.leetcode.com/uploads/2020/12/14/tree1.jpg\")
\n\nInput: root = [2,1,3]\nOutput: 1\n\n\n
Example 2:
\n![\"\"](\"https://assets.leetcode.com/uploads/2020/12/14/tree2.jpg\")
\n\nInput: root = [1,2,3,4,null,5,6,null,null,7]\nOutput: 7\n\n\n
\n
Constraints:
\n\n[1, 104].-231 <= Node.val <= 231 - 1Compiled with clang 11 using the latest C++ 20 standard.
Your code is compiled with level two optimization (-O2). AddressSanitizer is also enabled to help detect out-of-bounds and use-after-free bugs.
Most standard library headers are already included automatically for your convenience.
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