Question

2. Inthe pseudocode program below, list is an initially empty Singly Linked List: The function populatelist() adds the integers [8, 5, 1, 5, 2, 7] to the tail of list sequentially. What is the output of the program? Select 'No Answer' if the program results in an error. populatelist(); int sum = 0; Node n = list.head; // list.head/list.tail points to the first/last integer in list sum += n.value; sum += n.value; sum += n.next.value; n = n.next; sum += n.value; print sum; No answer

Answer 1

Let's trace the program, one line at a time.

• populateList();
  • List is 8 -> 5 -> 1 -> 5 -> 2 -> 7
• int sum = 0;
  • Initializes variable sum to 0.
• Node n = list.head;
  • n points to head, i.e. 8.
• sum += n.value;
  • sum = sum + 8 = 0 + 8 = 8.
• sum += n.value;
  • Note that here n is still pointing to 8 only.
  • So, sum = sum + 8 = 8 + 8 = 16.
• sum += n.next.value;
  • n is pointing to 8, thus n.next will be 5.
  • So, sum = sum + 5 = 16 + 5 = 21.
• n = n.next;
  • Now, n points to 5.
• sum += n.value;
  • sum = sum + 5 = 21 + 5 = 26.
• print sum;
  • sum is printed.

Thus, the answer is

26