Tree101SymmetricTree

Pre-defined Methods

LinkedList

思路

镜面复制左边tree，直接和右边用Tree100SameTree比较

直接每level比较，但左边tree会在enqueue的时候颠倒左右顺序，从而和镜面对应位置的右边tree比较

第一遍做完一个test没有pass

[] 忘记考虑root为null的情况

Tricks总结

If no need to store the mirrorTree, don’t need to build the helper MirrorTree(). But as practice, we can write one.

If the first node in the Queue is not Root, but

Root.left

or

Root.right

, we need to consider

Root == null