CPN Computer Professional Examination Level II (CPE II) (Nigeria)

In systems programming, what is the primary difference between a pass-1 assembler and a pass-2 assembler?

• APass-1 defines symbols and builds the symbol table, while pass-2 generates machine code.
• BPass-1 resolves forward references, while pass-2 defines external references.
• CPass-1 parses high-level language tokens, while pass-2 performs code optimization.
• DPass-1 allocates memory segments, while pass-2 loads the object file into RAM.

Which of the following is a primary function of a linkage editor (linker) in a system compilation environment?

• ATranslating assembly language code directly into binary machine instructions.
• BCombining multiple object files and resolving external references into a single executabl…
• CAllocating memory space in RAM and loading the binary program for immediate execution.
• DConverting source code into intermediate representations and optimizing loop branches.

What is the role of a relocation register in a dynamic loading and memory management scheme?

• ATo hold the physical address of the page table root in virtual memory configurations.
• BTo store the size of the logical address space and raise exceptions on out-of-bounds acce…
• CTo hold the base physical address of the process, which is added to every logical address…
• DTo map file system directory descriptors to internal kernel stream structures.

During the compilation process, which phase is responsible for checking that the structure of the token sequence conforms to the grammar rules of the programming language?

• ALexical Analysis
• BSyntax Analysis (Parsing)
• CSemantic Analysis
• DCode Optimization

Which of the following loader schemes leaves the task of address allocation and reference resolution until the program is loaded into memory for execution?

• AAbsolute Loader
• BDirect-Linking Loader (Relocating Loader)
• CLinkage Editor
• DBootstrap Loader

What is a major advantage of using dynamic linking libraries (DLLs / Shared Libraries) over static libraries?

• ADynamic linking reduces the CPU overhead during library function calls.
• BShared libraries decrease the size of the executable file and save physical RAM by sharin…
• CDynamic linking guarantees that the program will run even if the target library file is d…
• DShared libraries eliminate the need for virtual-to-physical address translation.

Which of the following assembly language concepts describes a single instruction symbol that is expanded into multiple assembly language instructions during assembling?

• ADirective (Pseudo-instruction)
• BMacro
• CSubroutine (Procedure)
• DInterrupt Vector

Which table is created and maintained by a lexical analyzer to store identifiers and their associated attributes?

• AParse Table
• BSymbol Table
• CActivation Record
• DPage Directory

What is the purpose of the 'Relocation Bit' included in the object code format of a relocating assembler?

• ATo signal if an instruction contains a memory address that must be modified when loaded i…
• BTo represent the parity bit used to verify binary code integrity.
• CTo specify whether a subroutine should be executed in kernel mode or user mode.
• DTo identify the start address of the execution entry point.

In compilation, which optimization technique involves replacing a slow, high-level operation with an equivalent faster, lower-level operation?

• ADead-code Elimination
• BStrength Reduction
• CLoop Unrolling
• DConstant Folding

How does a system call handler transition execution from user space to kernel space?

• ABy calling a normal function pointer to the operating system code.
• BBy triggering a software interrupt or trap that switches the processor privilege level.
• CBy modifying the relocation register directly within the user program.
• DBy copying the system code into the stack segment of the active user process.

What is the primary role of an activation record (stack frame) in system runtime environments?

• ATo store data pages swapped out of physical memory by the virtual memory manager.
• BTo save local variables, parameters, return addresses, and register states for a function…
• CTo cache relational query results in temporary system file descriptors.
• DTo route network packets between socket interfaces using logical mapping.

Which memory section in a compiled binary process contains uninitialized global and static variables?

• ACode (Text) Segment
• BData Segment
• CBSS (Block Started by Symbol) Segment
• DHeap Segment

Which of the following intermediate code representations is commonly structured as a directed acyclic graph where nodes represent operators and leaves represent operands?

• AThree-address Code
• BAbstract Syntax Tree (AST)
• CPostfix Notation
• DSymbol Table

In Intel x86 assembly language, what is the effect of the directive 'EQU'?

• AIt reserves a specified number of bytes in the data segment.
• BIt defines a symbolic constant equal to a given expression or value.
• CIt compares two register operands for equality and sets flags.
• DIt marks the entry point of the main execution routine.

What is the primary function of a bootstrap loader in a computer system?

• ATo compile high-level system source code files into executable programs.
• BTo load the initial instructions of the operating system kernel into memory when the syst…
• CTo monitor active processes and swap out idle pages to virtual memory storage.
• DTo translate assembly commands to machine instructions during BIOS configuration.

What is the worst-case time complexity of inserting a node at the beginning of a singly linked list containing $N$ elements?

• A$O(1)$
• B$O(\log N)$
• C$O(N)$
• D$O(N \log N)$

Which of the following data structures operates on a Last-In, First-Out (LIFO) basis?

• AQueue
• BStack
• CBinary Search Tree
• DSingly Linked List

What is the worst-case time complexity of searching for an element in a binary search tree (BST) that is not balanced?

• A$O(1)$
• B$O(\log N)$
• C$O(N)$
• D$O(N^2)$

Which sorting algorithm uses a divide-and-conquer strategy, has a worst-case time complexity of $O(N^2)$, but has an average-case time complexity of $O(N \log N)$?

• AMerge Sort
• BQuicksort
• CInsertion Sort
• DHeap Sort

Which graph traversal algorithm uses a queue data structure to visit vertices level-by-level starting from a root node?

• ADepth-First Search (DFS)
• BBreadth-First Search (BFS)
• CKruskal's Algorithm
• DDijkstra's Algorithm

What is the primary characteristic of an AVL tree that distinguishes it from a standard binary search tree?

• AIt allows nodes to have up to three children.
• BThe keys in an AVL tree are stored in leaf nodes only.
• CThe difference in heights between the left and right subtrees of any node is at most 1.
• DIt maintains a sorted order by colors (red or black) assigned to nodes.

Which of the following describes the behavior of a circular queue implemented using an array of size $N$?

• AIt expands dynamically by doubling its capacity when full.
• BThe rear pointer wraps around to index 0 when it exceeds $N-1$ using modulo arithmetic.
• CIt allows elements to be inserted and deleted from both ends in $O(1)$ time.
• DIt uses a hash function to compute the storage location of each element.

What is the time complexity of searching for an element in an array using binary search, assuming the array is already sorted?

• A$O(1)$
• B$O(\log N)$
• C$O(N)$
• D$O(N \log N)$

Which binary tree traversal visits the nodes in the order: Left Subtree, Right Subtree, Root Node?

• AIn-order Traversal
• BPre-order Traversal
• CPost-order Traversal
• DLevel-order Traversal

In algorithm analysis, what does the Big-Omega ($\Omega$) notation represent?

• AThe tight bound or average-case running time of an algorithm.
• BThe asymptotic upper bound (worst-case) running time of an algorithm.
• CThe asymptotic lower bound (best-case) running time of an algorithm.
• DThe exact number of CPU clock cycles needed for instruction execution.

Which of the following is a key advantage of a doubly linked list over a singly linked list?

• AIt requires less memory overhead per node.
• BIt allows traversal in both forward and backward directions.
• CIt guarantees $O(1)$ time complexity for finding any element.
• DIt prevents memory fragmentation automatically.

What is the worst-case time complexity of sorting an array of $N$ elements using Merge Sort?

• A$O(N)$
• B$O(N \log N)$
• C$O(N^2)$
• D$O(2^N)$

Which of the following traversal sequences of a Binary Search Tree (BST) will output the keys in sorted ascending order?

• APre-order traversal
• BIn-order traversal
• CPost-order traversal
• DLevel-order traversal

What is the main advantage of using a binary heap instead of an unsorted array to implement a priority queue?

• AIt allows elements to be searched in $O(1)$ constant time.
• BIt reduces the time complexity of extracting the minimum or maximum element to $O(\log N)…
• CIt uses pointers instead of contiguous memory allocation.
• DIt allows duplicate elements to be resolved using hash chaining.

Which graph algorithm finds the shortest path from a single source vertex to all other vertices in a weighted graph with non-negative edge weights?

• APrim's Algorithm
• BDijkstra's Algorithm
• CFloyd-Warshall Algorithm
• DBellman-Ford Algorithm

What is a hash collision in a hash table data structure?

• AWhen the hash function returns a negative memory index.
• BWhen two different keys generate the same hash value and index.
• CWhen the hash table runs out of available memory.
• DWhen a search query fails to locate a key in the table.

What is the worst-case space complexity of Depth-First Search (DFS) on a graph, where $V$ is the number of vertices?

• A$O(1)$
• B$O(\log V)$
• C$O(V)$
• D$O(V^2)$

Which of the following database normal forms is defined by eliminating transitive dependencies on the primary key?

• AFirst Normal Form (1NF)
• BSecond Normal Form (2NF)
• CThird Normal Form (3NF)
• DBoyce-Codd Normal Form (BCNF)

What is the purpose of the COMMIT command in transactional SQL database systems?

• ATo temporarily save changes to a savepoint within the transaction.
• BTo permanently save all changes made during the current transaction to the database.
• CTo discard all changes made during the current transaction and restore the previous state.
• DTo release all lock structures currently held by active user sessions.

In the context of the ACID properties of a database transaction, what does the term 'Isolation' guarantee?

• AAll operations in a transaction are completed successfully, or none are.
• BOnce a transaction is committed, its changes survive system failures.
• CConcurrent execution of transactions leaves the database in the same state as if they wer…
• DTransactions must transition the database from one valid state to another, maintaining in…

What is the primary function of a database index?

• ATo enforce relational integrity constraints between parent and child tables.
• BTo speed up data retrieval operations by avoiding full table scans.
• CTo encrypt sensitive data columns using hashing algorithms.
• DTo partition large tables into smaller physical files.

Which type of join returns all rows from the left table, and the matched rows from the right table, filling with NULL values if there is no match?

• AINNER JOIN
• BLEFT OUTER JOIN
• CRIGHT OUTER JOIN
• DFULL OUTER JOIN

What concurrency control anomaly occurs when a transaction reads data that has been modified by another transaction but not yet committed?

• ADirty Read
• BNon-repeatable Read
• CPhantom Read
• DLost Update

In a relational database schema, what is a foreign key?

• AAn attribute used to uniquely identify each row in a table.
• BAn attribute in one table that references the primary key of another table to establish a…
• CA key generated by external APIs to authenticate query requests.
• DAn index used exclusively for text search operations.

What is the key difference between a B-tree index and a B+ tree index in modern database storage engines?

• AB-trees store data pointers only in leaf nodes, while B+ trees store them in all levels.
• BB+ trees store all actual data records or pointers in leaf nodes and connect them with a…
• CB-trees are binary search trees, while B+ trees support up to four children per node.
• DB+ trees are stored in main memory (RAM) only, while B-trees are stored on disk.

Under what condition is a relation in Boyce-Codd Normal Form (BCNF)?

• AIf it is in 3NF and has no composite primary keys.
• BIf for every non-trivial functional dependency $X \rightarrow Y$ in the relation, $X$ is…
• CIf it is in 2NF and has no multivalued dependencies.
• DIf it has no foreign key relationships with other tables.

Which SQL keyword is used in conjunction with aggregate functions to filter groups of rows based on a specified condition?

• AWHERE
• BHAVING
• CORDER BY
• DGROUP BY

What is the purpose of a database transaction log (write-ahead log)?

• ATo store database user passwords securely using encryption.
• BTo record all database modifications before they are applied to the data files, ensuring…
• CTo log search queries for performance auditing purposes.
• DTo hold temporary intermediate tables generated by complex join operations.

Which level of transaction isolation completely prevents dirty reads, non-repeatable reads, and phantom reads?

• ARead Uncommitted
• BRead Committed
• CRepeatable Read
• DSerializable

What is referential integrity in a relational database?

• AThe requirement that all tables must have a primary key.
• BThe requirement that every foreign key value must match an existing primary key value in…
• CThe process of backing up database tables to prevent data loss.
• DThe speed with which queries reference indexed tables.