#452 · #951 · Flip Equivalent Binary Trees(翻转等价二叉树)

For a binary tree T, a flip swaps a node's left and right children. Two trees are flip equivalent if one can be made identical to the other by a series of flips. Given two roots, return whether they are flip equivalent. Constraints: the number of nodes in each tree is in [0, 100], 0 <= Node.val <= 99.