Array ADT Operations · Data Structures and Algorithms

Array ADT Operations

CSC-211 · Semester III · Data Structures and Algorithms

beginner20 minAvailable

Array ADTContiguous storage · O(1) index access

Length

Comparisons

Writes

Index access is O(1) — that is why arrays beat lists for random reads. But inserting at the front shifts every element, costing O(n). Try inserting at index 0.

Lab brief

Objective

Learn how an array behaves as an Abstract Data Type by performing insert, delete, search and traversal operations at chosen positions.

Theory & concepts

An array is a fixed-capacity, index-ordered collection. As an ADT it exposes operations: get(i), set(i, v), insert at a position (which shifts elements right), and delete at a position (which shifts elements left). Inserting and deleting from the middle cost O(n) because every later element must move, while access by index is O(1).

Rendering diagram…

Array ADT operations and their costs

Capacity  N = 8
Insert at index i  → shift elements i..N-2 right, then write
Delete at index i  → shift elements i+1..N-1 left
Search  → linear scan, O(n)
Access  → arr[i], O(1)

Prerequisites

Lesson: Arrays and the linked list family
Basic understanding of index-based access

Instructions

1Inspect the initial array and the operation toolbar.
2Insert a value at a chosen index and watch the elements shift right.
3Delete from an index and watch the elements shift left.
4Search for a value and follow the linear scan highlight.
5Watch what happens when you insert into a full array (overflow).

Tasks

Insert in the middle
Insert 25 at index 3 and note which elements moved.
Delete from the front
Delete index 0 and observe the cost of shifting everything left.
Search behaviour
Search for a value present and one absent; compare the number of checks.

Self-check

Insert and delete preserve ordering and shift correctly.
The student can explain why middle insert/delete is O(n).
Index access is identified as O(1).

Environment

array viewinsertdeletesearchindex highlight