class Solution {
public:
/**
* @aaram a, b, the root of binary trees.
* @return true if they are identical, or false.
*/
bool isIdentical(TreeNode* a, TreeNode* b) {
if(a == NULL && b == NULL) return true;
if(a == NULL ) return false;
if(b == NULL ) return false;
return a->val == b->val && isIdentical(a->left,b->left) && isIdentical(a->right,b->right);
}
};
bool isSameTree(TreeNode *p, TreeNode *q) {
if (p == NULL || q == NULL) return (p == q);
return (p->val == q->val && isSameTree(p->left, q->left) && isSameTree(p->right, q->right));
}