Russia 11 класс Informatics (basic)
Chapters: 4
1. Digital literacy
Networks and Internet · Internet services and security
- Network Types, Topologies and Protocols: Size, Shape and Rules – Networks are grouped by size: PAN (a few metres around one person), LAN (a room, building or campus), MAN (a city) and WAN (a country or the world). A topology is the layout of how nodes are wired: bus (all on one backbone cable), star (all to a central hub or switch) and tree (stars joined in levels). A protocol is a set of rules: TCP/IP breaks and routes data on the Internet, HTTP and HTTPS carry web pages, FTP moves files, SMTP sends email, POP3 downloads email, PPP links two devices directly, TELNET logs into a remote computer, and VoIP carries voice calls over the Internet.
- Internet and Web: URL, Services, Websites, Hosting and Browsers – The Internet is a worldwide network of networks. The World Wide Web is the collection of web pages on it, linked by hyperlinks, and each page has an address called a URL. The Internet also carries email, chat and VoIP. A website is a group of related web pages; pages can be static (same for everyone) or dynamic (built for each visitor). A web server stores and sends pages, and web hosting keeps a site online. A browser displays pages, and its settings, add-ons, plug-ins and cookies change how it works.
2. Theoretical foundations
Modelling and graphs
- Graph Theory: Dots, Lines and Networks – A graph is a set of vertices (dots) joined by edges (lines). The degree of a vertex is how many edges touch it, and the sum of all degrees is twice the number of edges. An Euler trail uses every edge once and exists only when 0 or 2 vertices have odd degree. A tree is a connected graph with no cycles and n − 1 edges. Weighted graphs model roads and networks; Kruskal’s and Prim’s algorithms find a minimum spanning tree.
3. Algorithms and programming
Programming basics · Strings and arrays · Sorting
- Control Statements in Python: if-else, while and for – Normally Python runs lines one after another (sequence). Control statements change this flow. if-else chooses one of two paths; if-elif-else picks the first true condition from many. while repeats a block while a condition is true; for repeats once for each item of a sequence such as range(start, stop, step).
- Lists in Python: Create, Traverse, Change and List Methods – A list is an ordered, changeable collection written in square brackets, like [10, 20, 30]. Items are reached by index (from 0, or negative from the end) and slices. We traverse a list with a for loop, change items in place because lists are mutable, and use functions (len, max, min, sum, sorted, list) and methods (append, insert, extend, remove, pop, sort, reverse, count, index, clear) to work with it.
- Sorting Algorithms – A sorting algorithm puts a list in order. Bubble sort swaps neighbours, insertion sort slides each item into a sorted part, selection sort picks the smallest each time, and merge sort splits the list and merges sorted halves. Merge sort needs far fewer comparisons on long lists (about n log₂ n instead of about n²/2).
4. Information technologies
Data analysis · Modelling and databases
- Data Analysis – Data analysis means turning raw data into answers. It follows a cycle: ask a question, collect data, clean it (remove errors, repeats and blanks), organise and transform it, analyse it with summaries such as mean, median, range and patterns, show it with a good chart, and draw a careful conclusion. Watch for outliers, small samples and bias, and remember that a correlation between two things does not prove that one causes the other. Data must also be stored safely and used with permission.
- Database Concepts: DBMS, Relations and Keys – Keeping data in separate files causes duplication, inconsistency and poor security. A database stores related data in one organised place, and a DBMS (like MySQL) is the software that manages it. In the relational model, data is kept in tables (relations) made of columns (attributes) and rows (tuples); a domain is the set of allowed values of a column. A candidate key uniquely identifies each row; one is chosen as the primary key and the others are alternate keys.