public static DLList initialArr(String filePath)
{
FileStream f = new FileStream(filePath, FileMode.Open, FileAccess.Read);
DLList pDLL = new DLList();
string line;
try
{
StreamReader m_streamReader = new StreamReader(f);
//StreamReader read txt
m_streamReader.BaseStream.Seek(0, SeekOrigin.Begin);
//read from head to tail by lines
while ((line = m_streamReader.ReadLine()) != null)
{
Console.WriteLine(line);
// process every line
DLLNode p = new DLLNode(line);
pDLL.addToTail(p);
}
// Console.WriteLine("===============");
m_streamReader.Close();
}
catch (FileNotFoundException e)
{
Console.WriteLine("errors" + e.ToString());
}
return(pDLL);
}
static void Main(string[] args)
{
Console.WriteLine("Display the DDList:");
DLList p = initialArr("C:/Users/edgu1/Desktop/222525.txt");
Console.WriteLine("///////////////////////////////////");
Console.WriteLine("Enter the search number:");
string sn = Console.ReadLine();
DLLNode node = search(p, sn);
Console.WriteLine((node == null) ? "This number is not exist!" : ("The position of the " + node.str + " " + "is " + node.number));
Console.WriteLine("///////////////////////////////////");
Console.WriteLine("Removed number:");
DLLNode nodehead = removeHead(p);
Console.WriteLine(nodehead.str);
Console.WriteLine("Display the current DDList:");
printsAppearNumbers(p);
Console.WriteLine("///////////////////////////////////");
/*DLLNode nodetail = removeTail(p);
* Console.WriteLine(nodetail);*/
Console.WriteLine("Enter the node the you want to remove,please:");
string r = Console.ReadLine();
DLLNode delnode = new DLLNode(r);
removeNode(p, delnode);
Console.WriteLine("Display the current DDList:");
printsAppearNumbers(p);
Console.WriteLine("///////////////////////////////////");
}
} // removeHead
public void removeTail()
{
/* Changed this code as this would not remove the tail
* Original code:
* if (this.head == this.tail)
* {
* this.head = null;
* this.tail = null;
* return;
* }
* To this below: */
if (head == null)
{
return;
}
else if (head != tail)
{
tail = tail.previous;
tail.next = null;
}
else
{
head = tail = null;
}
} // remove tail
} // constructor
/*-------------------------------------------------------------------
* The methods below includes several errors. Your task is to write
* unit test to discover these errors. During delivery the tutor may
* add or remove errors to adjust the scale of the effort required by
*/
public void addToTail(DLLNode p)
{
//changed code
if (head == null)
{
head = p;
tail = p;
}
else
{
tail.next = p;
p.previous = tail;
p.next = null;
tail = p;
}
/*if (head == null)
* {
* head = p;
* tail = p;
* }
* else
* {
* tail.next = p;
* tail = p;
* p.previous = tail;
* }*/
} // end of addToTail
} // end of search (return pionter to the node);
public DLLNode removeNode(DLLNode p)
{ // removing the node p.
DLLNode rnode = null;
if (p != null)
{
p = search(p.str);
if (p != null)
{
rnode = p;
if (p.next == null)
{
p = this.tail;
this.tail = this.tail.previous;
this.tail.next = null;
p.previous = null;
return(rnode);
}
if (p.previous == null)
{
p = this.head;
this.head = this.head.next;
p.next = null;
this.head.previous = null;
return(rnode);
}
p.next.previous = p.previous;
p.previous.next = p.next;
p.next = null;
p.previous = null;
}
}
ordered();
return(rnode);
} // end of remove a node
} // removeHead
public void removeTail()
{
//change code
if (this.tail == null)
{
return;
}
if (this.head == this.tail)
{
this.head = null;
this.tail = null;
return;
}
this.tail = this.tail.previous;
this.tail.next = null;
return;
/*if (this.tail == null) return;
* if (this.head == this.tail)
* {
* this.head = null;
* this.tail = null;
* return;
* }*/
} // remove tail
} // end of search (return pionter to the node);
public void removeNode(DLLNode p)
{ // removing the node p.
//changed code
if (p == null || this.head == null) //checking whether p is null or empty list
{
return;
}
if (this.head == p && this.tail == p) //when there is only one node in a list
{
this.head = null;
this.tail = null;
return;
}
if (p.next == null) //when p is last node
{
this.tail = this.tail.previous;
this.tail.next = null;
p.previous = null;
return;
}
if (p.previous == null) //when p is the first node
{
this.head = this.head.next;
p.next = null;
this.head.previous = null;
return;
}
//when p is in middle position
p.previous.next = p.next;
p.next.previous = p.previous;
p.next = null;
p.previous = null;
return;
/*if (p.next == null)
* {
* this.tail = this.tail.previous;
* this.tail.next = null;
* p.previous = null;
* return;
* }
*
* if (p.previous == null)
* {
* this.head = this.head.next;
* p.next = null;
* this.head.previous = null;
* return;
* }
* p.next.previous = p.previous;
* p.previous.next = p.next;
* p.next = null;
* p.previous = null;
* return;*/
} // end of remove a node
} // remove tail
/*-------------------------------------------------
* Return null if the string does not exist.
* ----------------------------------------------*/
public void ordered()
{
int count = 0;
DLLNode p = head;
while (p != null)
{
count++;
p.number = count;
p = p.next;
}
}
} // end of removeNode()
public int total()
{
DLLNode p = head;
int total = 0;
while (p != null)
{
total++;
p = p.next;
}
return(total);
} // end of total
public static void printsAppearNumbers(DLList dll1)
{
DLLNode head = dll1.head;
// ArrayList list1 = new ArrayList ();
while (head.next != null)
{
Console.WriteLine(head.str);
head = head.next;
}
Console.WriteLine(head.str);
}
} // end of search (return pionter to the node);
public void removeNode(DLLNode p)
{ // removing the node p.
/* Cleaned this section, as I felt this code was too complicated for what it was trying to do.
* Replaced with the following code: (Previous code used is commented out)*/
DLLNode node = head;
while (node.num != p.num)
{
//Tested using testRemoveNode1
if (node.next == null)
{
/* Original code:
* this.tail = this.tail.previous;
* this.tail.next = null;
* p.previous = null;
* return;*/
return;
}
else
{
/* Original code:
* this.head = this.head.next;
* p.next = null;
* this.head.previous = null;
* return;*/
//Tested using testRemoveNode2
node = node.next;
}
}
//Tested using testRemoveNode3
if (node == head)
{
removeHead();
}
//Tested using testRemoveNode4
else if (node == tail)
{
removeTail();
}
else
{
//Tested using testRemoveNode2
node.previous.next = node.next;
node.next.previous = node.previous;
}
} // end of remove a node
} // end of search
public void removeNode(DLLNode p)
{
DLLNode node = head;
//base case (empty list)
if (head == null)
{
return;
}
//find the node
while (node.num != p.num)
{
if (node.next == null)
{
return; //node doesn't exist
}
else
{
node = node.next;
}
}
//1 node list
if (node == head && node == tail)
{
head = null;
tail = null;
}
else if (node == head)
//node is head
{
head = head.next;
head.previous = null;
}
else if (node == tail)
//node is tail
{
tail = tail.previous;
tail.next = null;
}
else
//node is neither head nor tail
{
node.next.previous = node.previous;
node.previous.next = node.next;
}
} // end of removeNode()
} // constructor
/*-------------------------------------------------------------------
* The methods below includes several errors. Your task is to write
* unit test to discover these errors. During delivery the tutor may
* add or remove errors to adjust the scale of the effort required by
*/
public void addToTail(DLLNode p)
{
if (head == null)
{
head = p;
tail = p;
}
else
{
tail.next = p;
tail = p;
p.previous = tail;
}
} // end of addToTail
} // end of addToHead
public DLLNode removeHead()
{
if (head == null)
{
return(null);
}
DLLNode p = head;
head = head.next;
head.previous = null;
p.next = null;
ordered();
return(p);
} // removeHead
} // end of addToTail
public void addToHead(DLLNode p)
{
if (head == null)
{
head = p;
tail = p;
}
else
{
p.next = this.head;
this.head.previous = p;
head = p;
}
} // end of addToHead
} // removeHead
public DLLNode removeTail()
{
if (this.tail == null)
{
return(null);
}
DLLNode p = tail;
tail = tail.previous;
p.previous = null;
tail.next = null;
ordered();
return(p);
} // remove tail
} // end of addToTail
public void addToHead(DLLNode p)
{
//Simplified code by removing "this."
if (head == null)
{
head = p;
tail = p;
}
else
{
p.next = head;
head.previous = p;
head = p;
}
} // end of addToHead
} // end of addToTail
public void addToHead(DLLNode p)
{
if (head == null)
{
head = p;
tail = p;
}
else
{
p.next = head;
head.previous = p;
head = p;
}
return;
} // end of addToHead
} // end of remove a node
public int total()
{
DLLNode p = head;
int tot = 0;
while (p != null)
{
/* Original code:
* tot += p.num;
* p = p.next.next;
*
* Changed to the code below :*/
p = p.next;
tot++;
}
return(tot);
} // end of total
public DLLNode search(String str)
{
int count = 0;
DLLNode p = head;
while (p != null)
{
count++;
p.number = count;
if (p.str == str)
{
break;
}
p = p.next;
}
return(p);
} // end of search (return pionter to the node);
} // removeHead
public void removeTail()
{
// corrected this code so that when tail is removed,
// the previous node becomes the tail
if (head == null)
{
return;
}
else if (head != tail)
{
tail = tail.previous;
tail.next = null;
}
else
{
head = null;
tail = null;
}
} // remove tail
} // remove tail
public DLLNode search(int num)
{
DLLNode p = head;
if (head == null)
{
return(null);
}
while (p != null)
{
if (p.num == num)
{
return(p);
}
p = p.next;
}
return(null);
} // end of search (return pionter to the node);
} // end of addToHead
public void removeHead()
{
if (head == null)
{
return;
}
// corrected this code so that when head is removed,
// next node becomes head & next node.previous is null
else if (head != tail)
{
head = head.next;
head.previous = null;
}
else //only 1 node in the list
{
head = null;
tail = null;
}
} // removeHead
} // remove tail
/*-------------------------------------------------
* Return null if the string does not exist.
* ----------------------------------------------*/
public DLLNode search(int num)
{
DLLNode p = head;
// if list is null, return null
if (p == null)
{
return(null);
}
while (p != null)
{
if (p.num.Equals(num))
{
return(p); // Returns pointer to node
}
p = p.next; // iterate through list AFTER checking num
}
return(null); // If p is null after while loop, return null (no match)
} // end of search
} // end of addToHead
public void removHead()
{
//changed code
if (this.head == null)
{
return;
}
if (this.head == this.tail)
{
this.head = null;
this.tail = null;
return;
}
this.head = this.head.next;
this.head.previous = null;
return;
/* if (this.head == null) return;
* this.head = this.head.next;
* this.head.previous = null;*/
} // removeHead
} // end of addToHead
public void removeHead()
{
//Edited this section of code by simplified it by removing "this."
//Tested using testRemoveHead2
if (head == null)
{
return;
}
else if (head != tail)
{
head = head.next;
head.previous = null;
}
else
{
head = tail = null;
}
} // removeHead
} // end of remove a node
public int total()
{
//changed code
DLLNode p = head;
int tot = 0;
while (p != null)
{
tot += p.num;
p = p.next;
}
return(tot);
/*DLLNode p = head;
* int tot = 0;
* while (p != null)
* {
* tot += p.num;
* p = p.next.next;
* }
* return (tot);*/
} // end of total
} // remove tail
/*-------------------------------------------------
* Return null if the string does not exist.
* ----------------------------------------------*/
public DLLNode search(int num)
{
//change code
DLLNode p = head;
while (p != null)
{
if (p.num == num)
{
break;
}
p = p.next;
}
return(p);
/*DLLNode p = head;
* while (p != null)
* {
* p = p.next;
* if (p.num == num) break;
* }
* return (p);*/
} // end of search (return pionter to the node);
public DLLNode tail; // pointer to the tail of the list
public DLList()
{
head = null; tail = null;
} // constructor
public DLLNode previous; // pointer to the previous node
public DLLNode(int num)
{
this.num = num;
next = null;
previous = null;
} // end of constructor
