Computer Memory Basics

Memory as a Bounded Canvas

• Memory is a structured grid of slots, called memory addresses, with limited capacity.
• Each slot stores a unit of data, typically a byte (8 bits).

Data Representation

• Computers store data as bits (0s and 1s).
• Multiple bits combine to form numbers, characters, and data types.
• Numbers are stored in binary (base-2). For example, 1 in an 8-bit system is 00000001.

Memory Slot Usage

• Slots are allocated sequentially for data needing more than one slot (e.g., integers, arrays, strings).
• Allocation depends on the data type. For example, 32-bit integers use 4 slots.

Fixed-Width Integers

• Fixed-width integers use the same amount of memory regardless of their value.
• A 32-bit integer always takes 4 slots, even a small value like 1 or 0.

Pointers

• Pointers store the address of another memory slot, not the data itself.
• This allows efficient referencing without data duplication and enables non-contiguous memory storage.

Strings

• Strings are sequences of numbers (mapped via standards like ASCII).
• Each character is stored in separate, sequential memory slots, like an array.

Efficient Access

• Computer access memory slots directly and quickly.
• Direct access makes operations like fetching an element from an array efficient.

Space Complexity

• Memory is finite, so efficient memory use is crucial.
• Space complexity measures how much memory an algorithm or data structure needs, affecting performance.

Coding Interview Relevance

Array Access

• Arrays store data contiguously, providing O(1) time to access elements by index.

Linked Lists

• Linked lists use pointers to connect elements that might not be stored consecutively.

Dynamic Data Structures

• Structures like hash maps and binary trees utilize pointers for flexible memory allocation and traversal.

Understanding Constraints

• Recognizing memory limitations is important for designing space-efficient algorithms.

Explore the fundamental concepts of computer memory including its structure, data representation, and allocation. Learn about memory slots, fixed-width integers, and the role of pointers in efficient data management.