LeetCode 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.

        if(p==q)
            return true;
        if(p==null && q==null)
            return true;
        if(p==null || q==null)
        {
            return false;
        }
        if(p.val!=q.val)
            return false;
        return isSameTree(p.left, q.left) && isSameTree(p.right, q.right);