# Cycle Detection

### Problem Statement :

```A linked list is said to contain a cycle if any node is visited more than once while traversing the list. Given a pointer to the head of a linked list, determine if it contains a cycle. If it does, return 1. Otherwise, return 0.

Example

head refers 1 -> 2 -> 3 -> NUL

The numbers shown are the node numbers, not their data values. There is no cycle in this list so return 0.

head refers 1 -> 2 -> 3 -> 1 -> NULL

There is a cycle where node 3 points back to node 1, so return 1.

Function Description

Complete the has_cycle function in the editor below.

It has the following parameter:

Returns

int: 1 if there is a cycle or 0 if there is not
Note: If the list is empty, head will be null.

Input Format

The code stub reads from stdin and passes the appropriate argument to your function. The custom test cases format will not be described for this question due to its complexity. Expand the section for the main function and review the code if you would like to figure out how to create a custom case.```

### Solution :

```                            ```Solution in C :

In C++ :

/*
Detect loop in a linked list
List could be empty also
Node is defined as
struct Node
{
int data;
struct Node *next;
}
*/
{
// Complete this function
// Do not write the main method

while (slowp && fastp && fastp->next)
{
slowp = slowp->next;
fastp  = fastp->next->next;

if (slowp == fastp)
{
return 1;
}
}

return 0;
}

In Java :

/*
Insert Node at the end of a linked list
head pointer input could be NULL as well for empty list
Node is defined as
class Node {
int data;
Node next;
}
*/

return 0;

return 1;

while(fast!=null)
{

fast=fast.next;
if(fast!=null)
fast=fast.next;
else
return 0;

slow=slow.next;

if(slow==fast)
return 1;

}
return 0;

}

In C :

// Complete the has_cycle function below.

/*
*
*     int data;
* };
*
*/

while((slow!=NULL)&&(fast!=NULL)&&(fast->next!=NULL))
{
slow=slow->next;
fast=fast->next->next;
if(slow==fast)
return 1;
}
return 0;

}

In python3 :

"""
Check if linked list has cycle
head could be None as well for empty list
Node is defined as

class Node(object):

def __init__(self, data=None, next_node=None):
self.data = data
self.next = next_node

return 0 if no cycle else return 1
"""

count = 0
while slow and fast and count==0:
if slow == fast:
count=1
else:
slow= slow.next
fast = fast.next.next
if fast !=None or count == 1:
return(1)
else:
return(0)```
```

## Costly Intervals

Given an array, your goal is to find, for each element, the largest subarray containing it whose cost is at least k. Specifically, let A = [A1, A2, . . . , An ] be an array of length n, and let be the subarray from index l to index r. Also, Let MAX( l, r ) be the largest number in Al. . . r. Let MIN( l, r ) be the smallest number in Al . . .r . Let OR( l , r ) be the bitwise OR of the

## The Strange Function

One of the most important skills a programmer needs to learn early on is the ability to pose a problem in an abstract way. This skill is important not just for researchers but also in applied fields like software engineering and web development. You are able to solve most of a problem, except for one last subproblem, which you have posed in an abstract way as follows: Given an array consisting

## Self-Driving Bus

Treeland is a country with n cities and n - 1 roads. There is exactly one path between any two cities. The ruler of Treeland wants to implement a self-driving bus system and asks tree-loving Alex to plan the bus routes. Alex decides that each route must contain a subset of connected cities; a subset of cities is connected if the following two conditions are true: There is a path between ever

## Unique Colors

You are given an unrooted tree of n nodes numbered from 1 to n . Each node i has a color, ci. Let d( i , j ) be the number of different colors in the path between node i and node j. For each node i, calculate the value of sum, defined as follows: Your task is to print the value of sumi for each node 1 <= i <= n. Input Format The first line contains a single integer, n, denoti

## Fibonacci Numbers Tree

Shashank loves trees and math. He has a rooted tree, T , consisting of N nodes uniquely labeled with integers in the inclusive range [1 , N ]. The node labeled as 1 is the root node of tree , and each node in is associated with some positive integer value (all values are initially ). Let's define Fk as the Kth Fibonacci number. Shashank wants to perform 22 types of operations over his tree, T

## Pair Sums

Given an array, we define its value to be the value obtained by following these instructions: Write down all pairs of numbers from this array. Compute the product of each pair. Find the sum of all the products. For example, for a given array, for a given array [7,2 ,-1 ,2 ] Note that ( 7 , 2 ) is listed twice, one for each occurrence of 2. Given an array of integers, find the largest v