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/** * Definition for binary tree * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */ class Solution { public: bool isSameTree(TreeNode *p, TreeNode *q) { if(q==NULL && p==NULL) return true; if(q==NULL || p==NULL) return false; return p->val==q->val && isSameTree(p->left,q->left) && isSameTree(p->right,q->right); } };