PROBLEM 4: a. (5 points) Consider the following picture of a min-heap holding 13 distinct integers (nodes with the value o are considered empty). Circle all nodes (if any) whose values will change as a result of one extractMin() operation. b. (7 points) Consider the following min-heap. i. (2 points) Fill in the array representation of the heap in the boxes below. The 'X' in the array at index 0 marks that position as unused. XIII ii. (3 points) Now fill in the array representation of the heap after inserting the value 15. iii. (2 points) Finally, fill in the array representation of the heap after decreasing the value of the shaded node to 20. Use your answer in part (ii) above as the starting point for this operation