Final answer:
To determine whether t2 represents a subtree of t1, a recursive algorithm can be used to compare the nodes of the trees. The time complexity is O(m * n) and the space complexity is O(max(m, n)). The algorithm will still work even if duplicate values are permitted in the trees.
Step-by-step explanation:
i) To determine whether t2 represents a subtree of t1, we can use a recursive algorithm. The algorithm checks if the current nodes of t1 and t2 are equal. If they are, it recursively checks if the left and right subtrees of t1 and t2 are also equal. This process continues until either t2 is exhausted or a mismatch is found. If t2 is exhausted, it means t2 is a subtree of t1.
ii) The time complexity of the algorithm is O(m * n), where m is the number of nodes in t1 and n is the number of nodes in t2. The space complexity is O(max(m, n)), as the recursive call stack can go as deep as the maximum height of the trees.
iii) The algorithm will still work if duplicate values are permitted in the trees. This is because the comparison is done based on the equality of nodes, and duplicate values do not affect the structure of the trees. The same algorithm can be used without any modifications.