- To do this project, you must obtain a copy of the prepared
files with these commands:
mkdir ~/cs171/hw7 cp /home/cs171000/Handouts/hw7/*.java ~/cs171/hw7
- This homework consists of 2 parts:
- Part 1:
- Write the void put(x, k) method that inserts a node containing the value x at the position k of the list
- Part 2:
- Write the
double remove(k) method
that removes the node at the
position k
of the list
The double remove(k) method must return the value in the deleted node
- Write the
double remove(k) method
that removes the node at the
position k
of the list
- Part 1:
- Suppose the list is as follows:
We will call:
- The node with value 9, the node at position 1
- The node with value 7, the node at position 2
- The node with value 4, the node at position 3
- The node with value 6, the node at position 4
- Assignment:
- Edit the
file List.java
and write the
void put(x, k) method
that inserts a node containing the value
x at the
position k
of the list
- Test program file used in part 1:
- testProg1.java
- Compile and run:
javac testProg1.java java testProg1
Correct result is:
Testing the put() method Insert 1 is correct ! myList = [7.0] Insert 2 is correct ! myList = [6.0 , 7.0] Insert 3 is correct ! myList = [1.0 , 6.0 , 7.0] Insert 4 is correct ! myList = [1.0 , 2.0 , 6.0 , 7.0] Insert 5 is correct ! myList = [1.0 , 2.0 , 3.0 , 6.0 , 7.0] Insert 6 is correct ! myList = [1.0 , 2.0 , 3.0 , 4.0 , 6.0 , 7.0] Insert 7 is correct ! myList = [1.0 , 2.0 , 3.0 , 4.0 , 5.0 , 6.0 , 7.0] Insert 8 is correct ! myList = [1.0 , 2.0 , 3.0 , 4.0 , 5.0 , 6.0 , 7.0 , 8.0] Insert 9 is correct ! myList = [1.0 , 2.0 , 3.0 , 4.0 , 5.0 , 6.0 , 7.0 , 8.0 , 9.0]
- Edit the
file List.java
and write the
void put(x, k) method
that inserts a node containing the value
x at the
position k
of the list
- What must the put(x,k)
algorithm do:
- The put(x,k) can
insert a node at
any position in the list
- The value k will determine the insert position
Examples:
- If the list is like this:
Then put(999, 1) will insert a node with valye 999 at position 1.
The list will be updated to:
- If the list is like this:
Then put(999, 3) will insert a node with valye 999 at position 3.
The list will be updated to:
- If the list is like this:
Then put(999, 5) will insert a node with valye 999 at position 5.
The list will be updated to:
- The put(x,k) can
insert a node at
any position in the list
- Hint:
- You must use a loop to find these
2 nodes:
the node at position k−1
and the node at position k
- Use 2 pointer variables
(ptr1 and
ptr2) and
adapt
the
algorithm for finding
the one-before-the-deletion node
on this webpage:
to find the node at position k−1 and the node at position k.
- After you have found
these 2 nodes, you must
link
a new node
with the value x between
the node at ptr1
and the node at ptr2:
- You must use a loop to find these
2 nodes:
the node at position k−1
and the node at position k
- Warning:
- There is one special case that
you must take care of:
- Inserting the node at head
(start) of the list
(How can you detect this case ???)
- We have learned how to insert a node at the head of a list on this webpage: click here
- Inserting the node at head
(start) of the list
- There is one special case that
you must take care of:
- Assignment:
- Edit the
file List.java
and write the
double remove(k) method
that removes the node
at the
position k
of the list
The remove(k) method must return the value that was stored in the deleted node
- Test program file used in part 2:
- testProg2.java
- Compile and run:
javac testProg2.java java testProg2
Correct result is:
Delete 1 is correct ! x = 1.0 *** myList = [2.0 , 3.0 , 4.0 , 5.0 , 6.0 , 7.0 , 8.0 , 9.0] Delete 2 is correct ! x = 5.0 *** myList = [2.0 , 3.0 , 4.0 , 6.0 , 7.0 , 8.0 , 9.0] Delete 3 is correct ! x = 6.0 *** myList = [2.0 , 3.0 , 4.0 , 7.0 , 8.0 , 9.0] Delete 4 is correct ! x = 9.0 *** myList = [2.0 , 3.0 , 4.0 , 7.0 , 8.0] Delete 5 is correct ! x = 8.0 *** myList = [2.0 , 3.0 , 4.0 , 7.0] Delete 6 is correct ! x = 3.0 *** myList = [2.0 , 4.0 , 7.0] Delete 7 is correct ! x = 2.0 *** myList = [4.0 , 7.0] Delete 8 is correct ! x = 7.0 *** myList = [4.0] Delete 9 is correct ! x = 4.0 *** myList = []
- Edit the
file List.java
and write the
double remove(k) method
that removes the node
at the
position k
of the list
- What must the remove(k)
algorithm do:
- The remove(k) can
delete a node at
any position in the list
- The value k will determine the delete position
Examples:
- If the list is like this:
Then remove(1) will delete the node at position 1.
The list will be updated to:
- If the list is like this:
Then remove(3) will delete the node at position 3.
The list will be updated to:
- If the list is like this:
Then remove(4) will delete the node at position 4.
The list will be updated to:
- The remove(k) can
delete a node at
any position in the list
- Hint:
- You must use the same algorithm
(discussed above)
to find these
2 nodes:
the node at position k−1
and the node at position k
- After you have found
these 2 nodes, you can delete
the node at
position k by
changing this link:
- You must use the same algorithm
(discussed above)
to find these
2 nodes:
the node at position k−1
and the node at position k
- Warning:
- There is one special case that
you must take care of:
- Deleting the node at head
(start) of the list
(How can you detect this case ???)
- We have learned how to delete a node at the head of a list on this webpage: click here
- Deleting the node at head
(start) of the list
- There is one special case that
you must take care of:
- Use the following command
(from inside your
cs171/hw7 project directory)
to turn in your program:
cd ~/cs171/hw7 /home/cs171000/turnin List.java hw7