Performing set operations on hash sets
a) Allow user to enter two set of staff names, one for those who play cricket and one for those
who play tennis.
b) Read and store the names in two HashSet objects.
c) Using these two sets perform the necessary operations to print the following:
i. The names of staff playing both cricket and tennis
ii. The names of staff playing either one or both
iii. The names of staff playing cricket but not tennis
iv. The names of staff playing tennis but not cricket
