Table of Contents

## How do you add a key to an array?

When adding a key-value pair to an array, you already have the key, you don’t need one to be created for you. Pushing a key into an array doesn’t make sense. You can only set the value of the specific key in the array. You can use the union operator ( + ) to combine arrays and keep the keys of the added array.

## How do you add a value to a NumPy array?

You can add a NumPy array element by using the append() method of the NumPy module. The values will be appended at the end of the array and a new ndarray will be returned with new and old values as shown above. The axis is an optional integer along which define how the array is going to be displayed.

## Is empty linked list C?

If the linked list is empty, then the value of the head is NULL. In C, we can represent a node using structures. Below is an example of a linked list node with integer data.

## How do you create a cycle in a linked list?

- # Function to detect a cycle in a linked list using hashing.
- def detectCycle(head): curr = head.
- s = set() # traverse the list.
- while curr:
- if curr in s:
- # insert the current node into the set.
- # move to the next node.
- # we reach here if the list does not contain any cycle.

## Why is a fast pointer moved by 2?

Why increase pointer by two while finding loop in linked list, why not 3,4,5? One pointer( slower/tortoise ) is increased by one and other pointer( faster/hare ) is increased by 2. When they are equal we find the loop and if faster pointer reaches null there is no loop in the linked list.

## What are fast and slow pointers?

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.

## Can we reverse a linked list using fast and slow pointers?

In the following code with a stringy Linked List, I created 2 pointers, fast and slow. I move fast pointer to the end and slow pointer to the middle. For example, let’s say the LinkedList has 1->2->4->8->5 . After reverse(slow), the slow pointer points to 5->8->4 , which is good.

## What is Floyd cycle detection algorithm?

Floyd’s cycle-finding algorithm is a pointer algorithm that uses only two pointers, moving through the sequence at different speeds. At each iteration, you move one of the pointers by two steps and the other one by one step. So you have two pointers tortoise and the hare.

## What is cycle in algorithm?

In computer science, cycle detection or cycle finding is the algorithmic problem of finding a cycle in a sequence of iterated function values. Floyd’s tortoise and hare algorithm moves two pointers at different speeds through the sequence of values until they both point to equal values.

## How do you find the cycles in a graphing algorithm?

To detect cycle, check for a cycle in individual trees by checking back edges. To detect a back edge, keep track of vertices currently in the recursion stack of function for DFS traversal. If a vertex is reached that is already in the recursion stack, then there is a cycle in the tree.