[Leetcode] symmetric

1: Recursion

Public class solution {public Boolean issymmetric (treenode root) {If (root = NULL) return true; return istwotreesypolicric (root. left, Root. right);} public Boolean istwotreesypolicric (treenode node1, treenode node2) {If (node1 = NULL & node2 = NULL) return true; if (node1 = NULL | node2 = NULL) return false; If (node1.val! = Node2.val) return false; return istwotreesypolicric (node1.left, node2.right) & istwotreesypolicric (node1.right, node2.left );}}

2: Non-recursion

 

[Leetcode] symmetric