Given two binary trees, write a function to check if they are equal or not.
Two binary trees are considered equal if they are structurally identical and the nodes have the same value.
空值判断+递归
public boolean isSameTree(TreeNode p, TreeNode q) { if ((p == null && q != null) || (p != null && q == null)) return false; else if (p == null && q == null) return true; else { if (p.val != q.val) { return false; } else { return ( isSameTree(p.left, q.left) && isSameTree(p.right, q.right) ); } } }
[leetcode] 100. Same Tree 解题报告
原文：http://www.cnblogs.com/pulusite/p/7599866.html