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detect a cycle in linked list

YOU.com answered on February 3, 2021 Popularity 9/10 Helpfulness 2/10

answer detect a cycle in linked list

detect a cycle in linked list

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class ListNode:
    def __init__(self, val=0):
        self.val = val
        self.next = None

def has_cycle(head):
    if not head or not head.next:
        return False

    slow = head
    fast = head.next

    while slow != fast:
        if not fast or not fast.next:
            return False
        slow = slow.next
        fast = fast.next.next

    return True

Popularity 9/10 Helpfulness 2/10 Language python

Source: Grepper

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Contributed on Sep 11 2023

YOU.com

0 Answers Avg Quality 2/10

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Linked List Cycle

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Input: head = [3,2,0,-4], pos = 1
Output: true
Explanation: There is a cycle in the linked list, where the tail connects to the 1st node (0-indexed).

Popularity 10/10 Helpfulness 1/10 Language whatever

Source: leetcode.com

Tags: cycle cycl

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Contributed on Feb 03 2021

Mysterious Macaque

0 Answers Avg Quality 2/10

cpp detect cycle in linked list

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// my solution might look lengthy but go it is made in a way to give you idea about
// --making a linked list with a cycle and detecting it, using a beautiful easy algorithm.
//AIGHT bru, LESSGO!
#include<bits/stdc++.h>
using namespace std;
class node{
	public:
		int data;
		node* next;
		node(int val)
		{
			data=val;
			next=NULL;
		}
};//creating linked list.
void insertatend(node* head, int val)
{
	node*n=new node(val);
	if(head==NULL) 
	{
		head=n;
		return;
	}
	node* temp=head;
	while(temp->next !=NULL)
	{
		temp=temp->next;
	}
	temp->next=n;
}
void makecycle(node* head, int pos)
{
	node*temp=head;
	int count=1;
	node* supernode;
	while(temp->next !=NULL)
	{
		if(count==pos){
			supernode=temp;
		}
		temp=temp->next;
		count++;
	}
	temp->next=supernode;
}//cycle has been made,
//NOW LETS TRY TO MAKE HARE AND RABBIT ALGORITHM OR FLOYD'S ALGORITHM TO DETECT A CYCLE IN A LINKED LIST
bool detectcycle(node* head)
{
	node* slow= head;
	node* fast= head;
	while(fast!=NULL && fast->next !=NULL)
	{
		slow=slow->next;
		fast=fast->next->next;
		if(fast==slow) return true;
	}
    return false;
}
void display(node* head)
{
	node*temp=head;
	while(temp!=NULL)
	{
		cout<<temp->data<<"->";
		temp=temp->next;
	}
	cout<<endl;
}
int main(){
    node*head= new node(1);
	insertatend(head,2);
	insertatend(head,3);
	insertatend(head,4);
	insertatend(head,5);
	insertatend(head,6);
	// linked list has been made.
	int pos;
	cin>>pos;
	display(head);
	makecycle(head,pos);
	
	if(detectcycle(head)) cout<<"yes";
	else cout<<"no";
}

Popularity 8/10 Helpfulness 1/10 Language cpp

Source: Grepper

Tags: c++ cycle

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Contributed on Jul 29 2022

ROCKETMAN

0 Answers Avg Quality 2/10

detect a cycle in linked list

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detect a cycle in linked list

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Linked List Cycle

cpp detect cycle in linked list

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