1. Computer Science 2

2. Be able to find someone in a linked list
Learning Targets
Be able to find someone in a linked list
Be able to delete someone from a linked list.
Be able to create a simple track database.

3. Type
ptrtype = ^rectype;
rectype = record
data:string;
phone:string;
next:ptrtype;
end;
Warm-up
With a partner, write a procedure for finding someone’s phone number that is in a linked list.
procedure FindNode(top:ptrtype; person:string);

4. Finding a node pseudo code
procedure FindNode(top:ptrtype;person:integer)
Search for a node with the value equal to person in the list.
If such a node is found, show the value.
procedure FindNode(top:ptrtype; person:string);
Var
currNode:ptrtype;
begin
currNode := top;
while (currNode<>nil) and (currNode^.data<> person) do
currNode := currNode^.next;
end;
if (currNode<>nil) then
writeln (person, ‘ phone number is ’, currNode^.phone)
else
writeln(person, ‘ was not found in the list’);
End;

5. Deleting a node Steps Like InsertNode, there are two special cases
DeleteNode(top:ptrtype; person:string)
Delete a node with the value equal to person from the list.
Steps
Find the desirable node (similar to FindNode)
Set the pointer of the predecessor of the found node to the successor of the found node
Release the memory occupied by the found node
Like InsertNode, there are two special cases
Delete first node
Delete the node in middle or at the end of the list

6. Deleting a node Pseudocode
Procedure DeleteNode(var top:ptrtype; person:string);
Var
prevNode, currNode:ptrtype;
begin
prevNode := nil;
currNode := top;
while (currNode<>nil) and (currNode^.data <> person) do
prevNode := currNode;
currNode := currNode^.next;
end;
if (currNode<>nil)then
if (prevNode<> nil) then
prevNode^.next := currNode^.next;
dispose(currNode);
end
else
top := currNode^.next;
End;
Try to find the node with its value equal to x

7. Deleting a node Procedure DeleteNode(var top:ptrtype; person:string);
prevNode, currNode:ptrtype;
begin
prevNode := nil;
currNode := top;
while (currNode<>nil) and (currNode^.data <> person) do
prevNode := currNode;
currNode := currNode^.next;
end;
if (currNode<>nil)then
if (prevNode<> nil) then
prevNode^.next := currNode^.next;
dispose(currNode);
end
else
top := currNode^.next;
End;
prevNode
currNode

8. Deleting a node Procedure DeleteNode(var top:ptrtype; person:string);
prevNode, currNode:ptrtype;
begin
prevNode := nil;
currNode := top;
while (currNode<>nil) and (currNode^.data <> person) do
prevNode := currNode;
currNode := currNode^.next;
end;
if (currNode<>nil)then
if (prevNode<> nil) then
prevNode^.next := currNode^.next;
dispose(currNode);
end
else
top := currNode^.next;
End;
front
currNode

9. Insertion Linked List Assignment #2
You will be creating a program for the running track events. (Note: Time will be kept in seconds)
Name
Event (Push: Let it support the participant running in up to 3 events.)
Best Time

10. What it needs to do. Enter the information Find a participant
Insertion linked list by name
Find a participant
Show their event and best time or say they are not in the list
Show all participants, events and times in order based on their name
Delete a person from the list
Pushes
Save to a file (Linked list to file)
Load from a file (File to linked list)
Enter an event and show all participants in that event
Enter and event and give lane assignments based on speed for an 8 lane track
4, 5, 3, 6, 2, 7, 1, 8