Explain the advantages of optimal binary search tree.

Optimal Binary Search Trees (OBST) have several advantages:

1. Efficiency: The primary advantage of an optimal binary search tree is its efficiency. It minimizes the total cost or time of searching for all elements in the tree. This is particularly beneficial when dealing with large data sets.

2. Balanced Structure: OBSTs are designed to be balanced, meaning the tree's height is minimized. This balance ensures that the maximum number of comparisons needed to find any item is as low as possible, improving the speed of search operations.

3. Dynamic Programming Solution: The problem of creating an OBST can be solved using dynamic programming, which breaks down the problem into simpler sub-problems. This approach makes the problem more manageable and the solution more efficient.

4. Predictable Performance: Since OBSTs are designed to minimize search cost, they offer predictable performance. This is particularly useful in applications where consistent performance is critical.

5. Optimized for Access Frequency: OBSTs are particularly beneficial when the frequency of access for each element is known. The tree is structured in such a way that elements that are accessed more frequently are found closer to the root of the tree, reducing the average search time.

6. Reduced Path Lengths: In an OBST, the average path length is minimized. This means that, on average, fewer nodes need to be traversed to find a particular element, speeding up search operations.