Which of the following are problems, and which are algorithms? 1. Quicksort. 2. Sorting an array into ascending order. 3. Listing all the prime numbers less than or equal to some natural number. 4....

Which of the following are problems, and which are algorithms?

1. Quicksort.

2. Sorting an array into ascending order.

3. Listing all the prime numbers less than or equal to some natural number.

4. Deciding whether one number evenly divides another.

5. "To factor a natural number, n, into prime factors, make a list of the prime numbers less than or equal to n. Then step through this list until you find a prime, p, that evenly divides n. Add p to a list of prime factors, and then repeat on n/p."

6. Playing a winning game of chess.

7. The following Java code fragment:

 int total = 0;

 for (int i = 1; i <=>

8. Finding and correcting the bugs in a computer program.