Floyd’s cycle-finding algorithm is
a pointer algorithm that uses only two pointers, moving through the sequence at different speeds
. It states the usage of Linked List in this algorithm and its output. The purpose is to determine whether the linked list has a cycle or not.
How does tortoise and hare algorithm work?
The idea behind the algorithm is that, if you have two pointers in a linked list, one moving twice as fast (the hare) than the other (the tortoise), then if they intersect, there is a cycle in the linked list. If they don’t intersect, then there is no cycle.
How can you detect a loop in a linked list and find its length using Floyd’s cycle?
Find the common point in the loop by using the Floyd’s Cycle detection algorithm.
Store the pointer in a temporary variable and keep a count = 0
.
Traverse the linked list until the same node is reached again and increase the count while moving to next node.
Print the count as length of loop.
How does Floyd’s slow and fast pointers approach work?
We have discussed Floyd’s fast and slow pointer algorithms in Detect loop in a linked list. The algorithm is to start two pointers, slow and fast from head of linked list. We move slow one node at a time and fast two nodes at a time. If there is a loop, then they will definitely meet.
Why does Floyd algorithm work?
Floyd-Warshall Algorithm is an algorithm for
finding the shortest path between all the pairs of vertices in a weighted graph
. This algorithm works for both the directed and undirected weighted graphs. But, it does not work for the graphs with negative cycles (where the sum of the edges in a cycle is negative).
How can we detect cycle in linked list?
- Have a visited flag with each node.
- Traverse the linked list and keep marking visited nodes.
- If you see a visited node again then there is a loop.
What is turtle algorithm?
Basic concept
A turtle is moved by one.
At the same time, a rabbit is moved by two. After starting at the same start point, then if the turtle meets up the rabbit again, it means this liked list has a loop. However, the rabbit reaches a goal (the last node) ahead of the turtle.
What is the space complexity for detecting a linked list?
Python Code for Two Pointer Approach
Time Complexity: O(N), where N is the number of nodes of the linked list. Space Complexity:
O(1)
, as a map is used.
What is a cycle check?
A cycle check or loop check
checks for paths where the last node already appears on the path from the start node to that node
.
How would you detect and remove a loop in a linked list?
Write a function detectAndRemoveLoop() that checks whether a given Linked List contains loop and if loop is present then removes the loop and returns true
. If the list doesn’t contain loop then it returns false.
How do you find the length of a loop?
The loop length of the open knitted structure (l) defined by Peirce [12] is:(2)
L = 2 A + B + 5.94 d
where A = loop width, B = loop height, d = yarn thickness.
What is linear linked list?
A linked list is
a linear data structure where elements are not stored at contiguous location
. Instead the elements are linked using pointers. In a linked list data is stored in nodes and each node is linked to the next and, optionally, to the previous.
What is fast and slow pointer Linkedlist?
Slow pointer and fast pointer are simply
the names given to two pointer variables
. The only difference is that, slow pointer travels the linked list one node at a time where as a fast pointer travels the linked list two nodes at a time.
How do you remove loops in a linked list or what are fast and slow pointers used for?
This approach uses a two-pointer – a fast pointer and a slow pointer
to determine if there exists a cycle in the loop
. The slow pointer moves one node ahead at a time, while the fast pointer moves two nodes ahead at a time. If a loop exists in the linked list, the fast and slow pointers are bound to meet at some point.
Why are you moving your fast pointer by two and not three?
Now by moving the fast pointer by two each step
they are changing their phase with each other; Decreasing their distance apart by one each step
. The fast pointer will catch up to the slow pointer and we can detect the loop.
How do you use Floyd algorithm?
How do you use Floyd’s algorithm?
Why are turtle graphics so popular?
Since the standard Python syntax, control flow, and data structures can be used alongside the turtle module,
turtle has become a popular way for programmers learning Python to familiarize themselves with the basics of the language
.
Are turtle graphics useful?
The onscreen pen that you use for drawing is called the turtle and this is what gives the library its name. In short, the Python turtle library
helps new programmers get a feel for what programming with Python is like in a fun and interactive way
. turtle is mainly used to introduce children to the world of computers.
What is turtle graphics explain in details using example?
Turtle is
a Python library to draw graphics
. After we import Turtle we can give commands like forward, backward, right, left etc. This commands will draw different shapes when we.
How do you find out if a linked list has an end ie the list is not a cycle?
The basic idea is to traverse the linked list, store the visited nodes, and If the visited node encounters again during the traversal, then it means there is a cycle. Otherwise,
if we reach the end of the linked list or discover a NULL pointer
, it means there is no cycle.
