data structures

data structures

1. Arrays

   • An array is a collection of items of the same variable type that are stored sequentially in memory. It’s one of the most popular and simple data structures and often used to implement other data structures.

2. Linked lists

   • A linked list is a linear sequence of nodes that are linked together. Each node contains a value and a pointer to the next node in the list. Unlike arrays, linked lists do not have indexes, so you must start at the first node and traverse through each node until you get to the nnth node. At the end, the last node will point to a null value. The first node is called the head, and the last node is called the tail. Below visualizes a singly linked list.

3. Stacks

   • Stacks are linear data structures in a LIFO (last-in, first-out) order. Now, what does that mean? Imagine a stack of plates. The last plate that you put on top of the stack is the first one you take out. Stacks work that way: the last value you add is the first one you remove.

4. Queues

   • Queues are very similar to stacks in that they both are linear data structures with dynamic size. However, queues are FIFO (first-in, first-out) data structures. To visualize this data structure, imagine you are lining up for a roller coaster. The first people that line up get to leave the line for the ride.

5. Graphs

   • A graph is a collection of vertices (nodes) that are connected by edges, creating a network.