Summary
Highlights
An algorithm is code that solves a problem. Functions take input, process it, and return output. Comparison operators result in boolean true/false values (expressions). Control flow is managed by statements like if/else (conditional logic) and loops (while, for) for iteration. Recursion and stack overflow errors are explained in the context of function calls.
Big-O notation is used to approximate algorithm performance (time and space complexity). Different algorithm types include brute force, divide and conquer (binary search), dynamic programming (with memoization), greedy algorithms (Dijkstra's), and backtracking algorithms.
A computer is explained as a Turing machine processing ones and zeros. The CPU contains transistors forming bits and bytes. Binary and hexadecimal systems are introduced for data representation. Machine code is discussed as the CPU-executable format, alongside RAM for data storage.
Operating system kernels manage hardware via device drivers. The shell provides a command-line interface to the OS, allowing connections to local and remote computers using SSH. Programming languages simplify computer interaction through abstraction, with interpreted (Python) and compiled (C++) types explained.
Programming languages use data types like integers, floats, characters, and strings. Variables attach names to data points. Dynamically typed (Python) vs. statically typed (C) languages are differentiated. Pointers for low-level memory control and garbage collection for automatic memory management are also covered.
Key data structures include arrays (indexed lists), linked lists (connected items), stacks (last-in, first-out), queues (first-in, first-out), and hashes/maps (key-value pairs). Non-linear structures like trees (hierarchical nodes) and graphs (connected nodes with edges) are also introduced.
Programming paradigms are introduced: declarative (what the program does, e.g., functional languages) and imperative (how to produce an outcome, e.g., procedural languages). Object-Oriented Programming (OOP) uses classes as blueprints for objects, encapsulating properties and methods. Inheritance allows code reuse and extends behaviors through subclasses.
Objects are instantiated from classes and stored in the memory heap for long-lived data, allowing objects to be passed by reference. The CPU contains multiple threads for simultaneous code execution (parallelism). Single-threaded languages use concurrency models like event loops or co-routines to handle multiple jobs.
Modern computing relies on virtual machines in the cloud, connected via the Internet Protocol (IP) and identified by IP addresses or URLs (DNS). TCP handshake and SSL provide secure connections. The Hypertext Transfer Protocol (HTTP) is used for data exchange, with APIs (Application Programming Interfaces) like REST offering standardized ways for clients to request data.