1. Jeff West - Quiz Section 16
CSE 143 Section AD
Quiz Section 16
8/9/2001
Jeff West - Quiz Section 16

2. Jeff West - Quiz Section 16
Announcements
Quiz – Stacks, Queues, Efficiency
Homework 5 Demo sign-up…
Final Review Sessions next Wednesday and Thursday nights – most likely 7pm both nights, location TBA
8 more days until our summer vacation…
8/9/2001
Jeff West - Quiz Section 16

3. Jeff West - Quiz Section 16
Agenda
Queue Examples From Last Time
Circle Drawing Example
Efficiency
8/9/2001
Jeff West - Quiz Section 16

4. Jeff West - Quiz Section 16
Copy Constructor
FlightQueue::FlightQueue(FlightQueue& other) {
front = back = NULL;
Node* curOfOther = other.front;
while(curOfOther != NULL) {
insert(curOfOther -> myFlight);
curOfOther = curOfOther -> next; }
8/9/2001
Jeff West - Quiz Section 16

5. Jeff West - Quiz Section 16
insert
void FlightQueue::insert(const Flight& newFlight) {
Node* addMe = new Node;
addMe -> myFlight = newFlight;
addMe -> next = NULL;
if(front == NULL)
front = back = addMe;
else {
back -> next = addMe;
back = addMe; }
8/9/2001
Jeff West - Quiz Section 16

6. Circle Drawing Example
The circle drawing program is downloadable from the section AD website under today’s date (8/9/2001).
8/9/2001
Jeff West - Quiz Section 16

7. Jeff West - Quiz Section 16
Efficiency
The idea is to get the “big picture”…
If you are running some function on an array of N elements, what does the running time look like…
Drop the lowest terms and constants to get the “big picture”…
Take the worst case…
8/9/2001
Jeff West - Quiz Section 16

8. Jeff West - Quiz Section 16
Efficiency Examples
N3 + 2N + 5 = O(N3)
9N5 + 8N4 + 3N + 17 = O(N5)
Heck, what about these ones?
N4 + 18N! + 12N3 = O(____)
2N + 12N – 19 = O(____)
8/9/2001
Jeff West - Quiz Section 16

9. Efficiency of a Nested Loop
for(int i = 0; i < size; i++)
for(int j = 0; j < 100; j++)
for(int k = j; k < size; k++)
cout << “Argh, what fun”;
Total cost is O(____) + O(____) + O(____)
The algorithm grows like O(____).
8/9/2001
Jeff West - Quiz Section 16

10. Efficiency of Linear Search
int Find(int A[], int N, int x) {
for(int i = 0; i < N; i++) {
if(A[i] == x)
return i;
return –1; }
A linear search like this grows like O(____).
8/9/2001
Jeff West - Quiz Section 16

11. Efficiency of Binary Search
Binary search deals with an array that is guaranteed to be in sorted order.
How much extra effort does it take to search if you double the size of the array?
How much effort is saved if you halve the size of the array?
8/9/2001
Jeff West - Quiz Section 16