1. Draw a decision tree and find the number of key comparisons in the worst and average cases for
a. the three-element basic bubble sort.
b. the three-element enhanced bubble sort (which stops if no swaps have been made on its last pass).
2. Design a comparison-based algorithm for sorting a four-element array with the smallest number of element comparisons possible.
3. Design a comparison-based algorithm for sorting a five-element array with seven comparisons in the worst case.