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.
Tree Depth-first Search
class Solution { public: bool isSameTree(TreeNode *p, TreeNode *q) { if(p==NULL&&q==NULL) return true; if(p==NULL||q==NULL||p->val!=q->val) return false; return isSameTree(p->left,q->left)&&isSameTree(p->right,q->right); } };
原文：http://www.cnblogs.com/Azhu/p/4326280.html