记录贴，互勉

1302. Deepest Leaves Sum
BFS
100. Same Tree
Recursive call itself
101. Symmetric Tree
Helper recursive call
104. Maximum Depth of Binary Tree
Helper recursive call

987. Vertical Order Traversal of a Binary Tree
Use map of the map to mark down the (pos, (level, val)) and bfs to traverse the tree
then re-visit the  map by its pos and level as keySet

110. Balanced Binary Tree
Compare rh and lh of the tree

572. Subtree of Another Tree
Check either the left or right of root is same subRoot

965. Univalued Binary Tree

102. Binary Tree Level Order Traversal
iterative and recursive solution

107. Binary Tree Level Order Traversal II
same as top-bottom, but add the same level value list to the beginning of the answer list  (ans.add(0,ls))

429. N-ary Tree Level Order Traversal

872. Leaf-Similar Trees

814. Binary Tree Pruning