Ruankao Programmer (Junior) case studies
Ruankao Programmer (Junior) · Put your knowledge to work in context.
This independent study page provides practice for Ruankao Programmer (Junior). Its editorial learning areas include Programming and Software Development; Computational Thinking and Problem Solving; Computer architecture, logic and data representation; Operating systems, translation and concurrency; Requirements, design, testing and architecture trade-offs; Data, Databases, and Information Retrieval; Computer Network Fundamentals and Architecture; Security foundations, governance and Chinese context. The Ruankao Programmer (Junior) case studies are 5 cases and about 3,327 words.
1The Recursive Path Counter That Freezes at 25 by 25
A student in a Java programming class writes a recursive method to count unique paths across a grid for a game. The method is: static long paths(int r, int c) { if (r == 0 c == 0) return 1; return paths(r-1, c) + paths(r, c-1); } It returns correct answers for 5×5 and 10×10 grids.
705 words, about 4 min2The Memory Hierarchy Upgrade Committee
A high school robotics team runs a simulation on 40 single-board computers. Each board has a 32 KB L 1 cache with a 1-cycle hit time, a unified L 2 cache with a 10-cycle hit time, and 100-cycle main memory.
633 words, about 3 min3The Slow Catalog Query
A public library's catalog database has 2.4 million rows in a table with columns id, title, author, year, subject, and checked out. The web catalog runs this query about 40 times per second: SELECT id, title FROM books WHERE author = ?
613 words, about 3 min4Candidate Records at East Mercia Examinations Board
East Mercia Examinations Board stores records for 25,000 candidates. Each record contains an 8-digit candidate number, a 60-character name, and nine paper marks that are integers from 0 to 100.
805 words, about 4 min5The Attendance App Breach
A district's attendance web app has 12,000 student and staff accounts. Passwords are stored as unsalted SHA-256 hashes.
571 words, about 3 min