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.
1 /** 2 * Definition for a binary tree node. 3 * struct TreeNode { 4 * int val; 5 * TreeNode *left; 6 * TreeNode *right; 7 * TreeNode(int x) : val(x), left(NULL), right(NULL) {} 8 * }; 9 */ 10 class Solution { 11 public: 12 bool isSameTree(TreeNode* p, TreeNode* q) { 13 if(!p&&!q) return true; 14 if(!p||!q) return false; 15 return p->val==q->val&&isSameTree(p->left,q->left)&&isSameTree(p->right,q->right); 16 17 } 18 };