I'm running into an issue where the last node in a linked list is replicated repeatedly.
- Parameter List1 = [1,2,4]
- Parameter List2 = [1,3,4]
- Expected Result = [1,1,2,3,4,4]
- Actual Result = [1,1,2,3,4,4,4,4,4,4,...]
Something happens in the final else statement before the return that duplicates the 4 multiple times and I can't figure out what it is. What is causing the the final node to behave like this? Is it a problem with my SinglyLinkedNode Class?
before current.next = list2
is executed the values are
- current = [1,1,2,3,4]
- list2 = [4]
after it is executed the values are
- current = [1,1,2,3,4,4,4,4,4,..]
- list2 = [1,1,2,3,4,4,4,4,4,...]
public static SinglyLinkedNode MergeTwoSortedLists(SinglyLinkedNode list1, SinglyLinkedNode list2)
{
//if one list is null, return the other
if (list1 == null) return list2;
if (list2 == null) return list1;
//declare the result node; declare the node that you will fill
SinglyLinkedNode result = new SinglyLinkedNode();
SinglyLinkedNode current = result;
//while neither lists are empty
while (list1 != null && list2 != null)
{
//do the comparisons and populate the current Node;
if (list1.val <= list2.val)
{
current.next = list1;
list1 = list1.next;
}
else
{
current.next = list2;
list2 = list2.next;
}
current = current.next;
}
//when one list is empty, use the remaining list to fill the current node
if (list1 != null)
{
current.next = list1;
}
else
{
current.next = list2;
}
return result.next;
}
public class SinglyLinkedNode
{
public int val;
public SinglyLinkedNode next;
public SinglyLinkedNode(int val = 0, SinglyLinkedNode next = null)
{
this.val = val;
this.next = next;
}
}
CodePudding user response:
I made a mistake when initializing the parameters because I had a list2 node point to a list1 node.
CodePudding user response:
First, and Must important concept
When you use the following code don't clone the Object, and clone the object's pointer. And in line 2 causes current.next
referenced to list1.next
after assignment.
1- current.next = list1;
2- list1 = list1.next;
But you can change your code like.
1- update your object public class SinglyLinkedNode : ICloneable
and implement this method.
public class SinglyLinkedNode : ICloneable
{
// other code
public object Clone()
{
return new SinglyLinkedNode(val, null);
}
}
2 - change here
//when one list is empty, use the remaining list to fill the current node
if (list1 != null)
{
current.next = list1;
list1 = list1.next;
}
else
{
current.next = list2;
list2 = list2.next;
}
--- Here, we have a nice example