Same Tree

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.

answer：

bool isSameTree(TreeNode* p, TreeNode* q) {
        if(p == NULL && q == NULL)
            return true;
        if((p != NULL && q!= NULL && (p->val == q->val))){
            if(isSameTree(p->left, q->left) && isSameTree(p->right, q->right))
                return true;
        }
        return false;
    }