Symmetric Tree Check

Create a function that checks whether a binary tree is symmetric around its center. A tree is symmetric if the left subtree is a mirror reflection of the right subtree. Input format: - The first line contains an integer N, the number of nodes in the tree. - The next N lines contain two integers L and R, representing the left and right children of each node respectively, where -1 indicates no child. Output format: - Output 'Yes' if the tree is symmetric, otherwise output 'No'. Example: Input: 3 1 1 -1 -1 -1 -1 Output: Yes