public static void SwapNodes(DoubleLinkedList selectedList, Node nodeOne, Node nodeTwo) //swaps two nodes on the list based on the reference of the node.
{
if (nodeOne.next.next == nodeTwo.prev || nodeTwo.next.next == nodeOne.prev) //Checks if the nodes are next to eachother.
{
if (nodeTwo.next == nodeOne.prev) //Checks if they are in the correct order being passed in.
{
SwapNodes(selectedList, nodeTwo, nodeOne); //Re-runs SwapNodes changing the order of nodes passed in.
}
else //Runs if the pairs are in the right order.
{
if (nodeOne.prev.prev == null && nodeTwo.next.next != null) //Checks if the pair is at the start of the list.
{
Node tempNode = new Node(); //Copy of nodeOne
tempNode.next = nodeOne.next.next;
tempNode.prev = nodeOne.prev.prev;
Node nodeRightOfTwo = new Node(); //Copy of nodeTwo
nodeRightOfTwo.next = nodeTwo.next.next;
nodeRightOfTwo.prev = nodeTwo.next.prev;
nodeTwo.prev.prev = null;
nodeTwo.next.next = nodeOne.prev;
nodeOne.prev.prev = nodeTwo.next;
nodeOne.next.next = nodeRightOfTwo.next;
nodeOne.next.next.prev = nodeOne.next;
selectedList.head = nodeTwo.prev;
}
else if (nodeTwo.next.next == null && nodeOne.prev.prev != null) //Checks if the pair is at the end of the list.
{
Node nodeLeftOfOne = new Node();
nodeLeftOfOne.prev = nodeOne.prev.prev;
nodeLeftOfOne.data = nodeOne.prev.data;
nodeLeftOfOne.next = nodeOne.prev.next;
nodeOne.next.next = null;
nodeOne.prev.prev = nodeTwo.next;
nodeTwo.next.next = nodeOne.prev;
nodeTwo.prev.prev = nodeLeftOfOne.prev;
nodeTwo.prev.prev.next = nodeTwo.prev;
}
else if (nodeTwo.next.next == null && nodeOne.prev.prev == null) //Checks if the pair is in a list of 2 length.
{
nodeTwo.next.next = nodeOne.prev;
nodeOne.prev.prev = nodeTwo.next;
nodeOne.next.next = null;
nodeTwo.prev.prev = null;
selectedList.head = nodeTwo.prev;
}
else //Checks if the pair is in a list greater than 3 but on neither end.
{
Node tempNodeLeftOne = new Node();
tempNodeLeftOne.prev = nodeOne.prev.prev;
tempNodeLeftOne.data = nodeOne.prev.data;
tempNodeLeftOne.next = nodeOne.prev.next;
nodeOne.prev.prev = nodeTwo.next;
nodeOne.next.next = nodeTwo.next.next;
nodeTwo.prev.prev = tempNodeLeftOne.prev;
nodeTwo.next.next = nodeOne.prev;
nodeTwo.prev.prev.next = nodeTwo.prev;
nodeOne.next.next.prev = nodeOne.next;
}
}
}
else //Runs if the pairs are far apart.
{
if (nodeOne.prev.prev == null && nodeTwo.next.next != null) //Checks if the pair is at the start.
{
Node tempNodeTwoFarLeft = new Node();
tempNodeTwoFarLeft.prev = nodeTwo.prev.prev;
tempNodeTwoFarLeft.data = nodeTwo.prev.data;
tempNodeTwoFarLeft.next = nodeTwo.prev.next;
Node tempNodeTwoFarRight = new Node();
tempNodeTwoFarRight.prev = nodeTwo.next.prev;
tempNodeTwoFarRight.data = nodeTwo.next.data;
tempNodeTwoFarRight.next = nodeTwo.next.next;
nodeTwo.prev.prev = null;
nodeTwo.next.next = nodeOne.next.next;
nodeTwo.next.next.prev = nodeTwo.next;
nodeOne.next.next = tempNodeTwoFarRight.next;
nodeOne.prev.prev = tempNodeTwoFarLeft.prev;
nodeOne.prev.prev.next = nodeOne.prev;
nodeOne.next.next.prev = nodeOne.next;
selectedList.head = nodeTwo.prev;
}
else if (nodeTwo.next.next == null && nodeOne.prev.prev != null) //Checks if the pair is at the end of the list.
{
Node tempNodeOneFarLeft = new Node();
tempNodeOneFarLeft.data = nodeOne.prev.data;
tempNodeOneFarLeft.prev = nodeOne.prev.prev;
tempNodeOneFarLeft.next = nodeOne.prev.next;
Node tempNodeOneFarRight = new Node();
tempNodeOneFarRight.data = nodeOne.next.data;
tempNodeOneFarRight.prev = nodeOne.next.prev;
tempNodeOneFarRight.next = nodeOne.next.next;
nodeOne.next.next = null;
nodeOne.prev.prev = nodeTwo.prev.prev;
nodeOne.prev.prev.next = nodeOne.prev;
nodeTwo.prev.prev = tempNodeOneFarLeft.prev;
nodeTwo.next.next = tempNodeOneFarRight.next;
nodeTwo.next.next.prev = nodeTwo.next;
nodeTwo.prev.prev.next = nodeTwo.prev;
}
else if (nodeTwo.next.next == null && nodeOne.prev.prev == null) //Checks if the pair are on opposite ends.
{
Node tempNodeOneOppositeRight = new Node();
tempNodeOneOppositeRight.data = nodeOne.next.data;
tempNodeOneOppositeRight.prev = nodeOne.next.prev;
tempNodeOneOppositeRight.next = nodeOne.next.next;
nodeOne.next.next = null;
nodeOne.prev.prev = nodeTwo.prev.prev;
nodeOne.prev.prev.next = nodeOne.prev;
nodeTwo.prev.prev = null;
nodeTwo.next.next = tempNodeOneOppositeRight.next;
nodeTwo.next.next.prev = nodeTwo.next;
selectedList.head = nodeTwo.prev;
}
else //Runs if the pair are in the centre.
{
Node tempNodeOneCentreLeft = new Node();
tempNodeOneCentreLeft.data = nodeOne.prev.data;
tempNodeOneCentreLeft.prev = nodeOne.prev.prev;
tempNodeOneCentreLeft.next = nodeOne.prev.next;
Node tempNodeOneCentreRight = new Node();
tempNodeOneCentreRight.data = nodeOne.next.data;
tempNodeOneCentreRight.prev = nodeOne.next.prev;
tempNodeOneCentreRight.next = nodeOne.next.next;
nodeOne.prev.prev = nodeTwo.prev.prev;
nodeOne.next.next = nodeTwo.next.next;
nodeOne.next.next.prev = nodeOne.next;
nodeOne.prev.prev.next = nodeOne.prev;
nodeTwo.prev.prev = tempNodeOneCentreLeft.prev;
nodeTwo.next.next = tempNodeOneCentreRight.next;
nodeTwo.prev.prev.next = nodeTwo.prev;
nodeTwo.next.next.prev = nodeTwo.next;
}
}
}
public static void MainProgram()
{
DoubleLinkedList primaryList = new DoubleLinkedList(); //Creates the main list for the program.
string fileName = "test.txt"; //String to hold the location of the file, located in /bin/debug
int commaCounter = 0; //Counter for looping through the first and second name.
StreamReader fileReader = new StreamReader(fileName); //Creates a StreamReader that will read the file in /bin/debug.
while (!fileReader.EndOfStream) //Executes until the end of the file
{
while (commaCounter != 2) //Loop for the first name and the second name.
{
int arrayPos = 1; //Used to keep track of the position in the array.
char[] charArray = new char[1]; //A char array to hold the data that will be inserted into the node.
char testchar = Convert.ToChar(fileReader.Read());
while (testchar != ',') //Reads the file until a comma is found.
{
if ((int)Convert.ToChar(testchar) == 32) //Checks if the character is a space.
{
//Do Nothing.
}
else //Adds to the char array if it's an alphabetical character.
{
charArray = ResizeArray(charArray, arrayPos); //Resizes the array to accommodate for the next character.
charArray[arrayPos - 1] = testchar; //Adds the character into the array.
arrayPos++; //Increases the position in the char array.
}
testchar = Convert.ToChar(fileReader.Read()); //Updates the character to the next character in the file.
}
InsertLast(primaryList, charArray); //Inserts the new char array into a node, inserts the node into the list.
foreach (char x in charArray) //Goes through all the elements in the char array
{
Console.Write(x); //Writes the characters to the console.
}
Console.WriteLine(); //Adds a line space.
commaCounter++;
}
fileReader.Read(); //Reads the space after the last name.
int newchar = fileReader.Read(); //A new char used to hold the current char in the file.
char[] numArray = new char[1]; //A new char array to hold the numbers.
int arrayNumPos = 1; //Holds the current position in the array.
while (newchar >= 48 && newchar <= 57) //Loop to make sure you only read if the value is a number.
{
numArray = ResizeArray(numArray, arrayNumPos); //Resizes the array to accommodate for the new character.
numArray[arrayNumPos - 1] = Convert.ToChar(newchar); //Adds the new character into the array.
newchar = fileReader.Read(); //Updates the character.
arrayNumPos++;
if (newchar < 48 || newchar > 57) //Catch incase newchar is changed into something that is not a number.
{
break; //Exits the while loop.
}
}
//Prints all of the numbers.
foreach (char num in numArray)
{
Console.Write(num);
}
Console.WriteLine(); //Adds space between every 3 nodes (every person).
fileReader.Read(); //removes the \n that adds a new line.
InsertLast(primaryList, numArray); //Inserts to the end of the array.
commaCounter = 0; //Resets the comma counter.
}
//PrintSurname(primaryList); //prints all of the surnames in the list
//PrintFirstname(primaryList); //prints all of the first names
//InsertionSortByLastname(primaryList); //runs insertion sort on the last name
//InsertionSortByFirstname(primaryList); //runs the insertion sort on the first name
//InsertionBySortID(primaryList); runs the insertion sort
}
