Answer:
Yes, the given list of entries L can be sorted by using a stable Radix-Sort with a bucket array of size 15. In Radix-Sort, the numbers are sorted digit by digit for each element in the list. In this case, each element in the list has two digits, so we will perform two passes through the list.
On the first pass, we will sort the list by the second digit (the ones place). This will result in the following intermediate list:
(1,2), (3,2), (15,1), (2,2), (3,3), (12,3), (2,12), (1,7), (13,12)
Note that the order of the elements with equal second digits is preserved, as required for a stable sort.
On the second pass, we will sort the list by the first digit (the tens place). This will result in the final sorted list:
(1,2), (1,7), (2,2), (2,12), (3,2), (3,3), (12,3), (13,12), (15,1)
Again, note that the relative order of the elements with equal first digits is preserved, because we used a stable sorting algorithm.
Therefore, we can use a stable Radix-Sort with a bucket array of size 15 to sort the given list of entries L.
Step-by-step explanation: