1. Computer Science
Sorting

2. Goals
Dry run review
Develop a process (pseudo code) and code to put a bunch of things in order.
Write a program that will sort an array of records.

3. Dry Run!! for count:= 5 downto 1 do
writeln(data[count].a:5, data[count].b:5:2);
for count:= 1 to 4 do
begin
with data[count] do
a := a + b;
b := a*b;
end;
for count:= 1 to 5 do
writeln(a,b:5:2)
end.
program Sample2;
type
rectype = record of
a:integer;
b:real;
end;
arraytype = array[1..5] of rectype;
var
data: arraytype;
count:integer;
begin
for count := 1 to 5 do
data[count].a:= 2* count;
data[count].b:= count -2;
for count:= 1 to 5 do
data[count].b:= data[count].b +data[count].a;

4. Sorting How do you put things in order? (Low to high) Pseudo-Code
Develop a sorting algorithm

5. So… How should this information be organized? Sorted by school?
Sorted by name?
Sorted by type of gift?
Today’s goal. Be able to sort an array of records using one of the sorts we have seen previously.

6. Bubble Sort Low High 8 2 6 9 21 1 Speed: O(n2) Stability: Stable
How it works: Check- Switch
Show it after each pass
Low High

7. Bubble Sort: To sort by name
{This is just the code for Bubble Sort}
for pass:= 1 to (size -1) do
begin
for check:= 1 to size-1 do
if TheArray[check] >TheArray[check+1] then
dummy:= TheArray[check];
TheArray[check]:= TheArray[check+1];
TheArray[check+1]:= dummy;
end;
end;{Of the for loop}

8. Array of Record Sorting Assignment
10 name/phone numbers
Get add the names and numbers
Set it up as a menu (with the while loop)
Show All
Sort by Name
Find Phone Number (Get a name and find the corresponding number)
Add a person (Push)
Quit
After the user searches for one name, let them search for other names, until they are done.
Push: Modify it to hold an unknown number of names.
Push: Develop a faster method to find the person taking advantage of the data being in order.