101. Symmetric TreeEasyGiven the root of a binary tree, check whether it is a mirror of itself (i.e., symmetric around its center). Example 1:Input: root = [1,2,2,3,4,4,3]Output: trueExample 2:Input: root = [1,2,2,null,3,null,3]Output: false Constraints:The number of nodes in the tree is in the range [1, 1000].-100 Follow up: Could you solve it both recursively and iteratively? # Definition fo..