public static void Main()
{
Console.WriteLine(@"Given a singly linked list of N nodes. Find if there is a cycle in the linked list
For example, if given linked list is 1->2->3->4->5 then output should be false.");
SingleLLNode <int> head = new SingleLLNode <int>(1);
SingleLLNode <int> node2 = new SingleLLNode <int>(2);
SingleLLNode <int> node3 = new SingleLLNode <int>(3);
SingleLLNode <int> node4 = new SingleLLNode <int>(4);
SingleLLNode <int> node5 = new SingleLLNode <int>(5);
SingleLLNode <int> node6 = new SingleLLNode <int>(6);
SingleLLNode <int> node7 = new SingleLLNode <int>(7);
head.next = node2;
node2.next = node3;
node3.next = node4;
node4.next = node5;
node5.next = node6;
node6.next = node7;
var slowp = head;
var fastp = head;
bool loopFound = false;
while (slowp != null && fastp != null && fastp.next != null)
{
slowp = slowp.next;
fastp = fastp.next.next;
if (slowp == fastp)
{
loopFound = true;
}
}
if (loopFound)
{
Console.WriteLine("Loop found");
}
else
{
Console.WriteLine("Loop not found");
}
}
public static void Main()
{
Console.WriteLine(@"Given a singly linked list of N nodes.
The task is to find middle of the linked list.
For example, if given linked list is 1->2->3->4->5 then output should be 3.");
SingleLLNode <int> head = new SingleLLNode <int>(1);
SingleLLNode <int> node2 = new SingleLLNode <int>(2);
SingleLLNode <int> node3 = new SingleLLNode <int>(3);
SingleLLNode <int> node4 = new SingleLLNode <int>(4);
SingleLLNode <int> node5 = new SingleLLNode <int>(5);
SingleLLNode <int> node6 = new SingleLLNode <int>(6);
SingleLLNode <int> node7 = new SingleLLNode <int>(7);
head.next = node2;
node2.next = node3;
node3.next = node4;
node4.next = node5;
node5.next = node6;
node6.next = node7;
//begin detection of middle node
var midNode = head;
var pointerNode = head;
int count = 0;
while (pointerNode != null)
{
pointerNode = pointerNode.next;
if (count % 2 == 1) // if odd
{
midNode = midNode.next;
}
count++;
}
Console.WriteLine($"Middle element is {midNode.data}");
Console.ReadLine();
}
public static void Main()
{
Console.WriteLine(@"Given a singly linked list of N nodes. The task is to reverse the linked list. ");
SingleLLNode <int> head = new SingleLLNode <int>(1);
SingleLLNode <int> node2 = new SingleLLNode <int>(2);
SingleLLNode <int> node3 = new SingleLLNode <int>(3);
SingleLLNode <int> node4 = new SingleLLNode <int>(4);
SingleLLNode <int> node5 = new SingleLLNode <int>(5);
SingleLLNode <int> node6 = new SingleLLNode <int>(6);
SingleLLNode <int> node7 = new SingleLLNode <int>(7);
head.next = node2;
node2.next = node3;
node3.next = node4;
node4.next = node5;
node5.next = node6;
node6.next = node7;
// trying the most effecient method.
//avoiding multiple iteration
var next = head;
var current = head;
var prev = head;
while (current != null)
{
next = current.next;
current.next = prev;
prev = current;
current = next;
}
head = prev;
while (head != null)
{
Console.WriteLine($"{head.data}");
}
Console.ReadLine();
}
