CS: 2.2 Problem Solving and Programming

Describe what Sequence is in programming constructs

Code is executed line-by-line, from top to bottom.

Explain Branching in programming constructs

A certain block of code is run if a specific condition is met, using IF statements.

How is Iteration defined in programming constructs?

A block of code is executed a certain number of times or while a condition is met, using loops like FOR, WHILE, or REPEAT UNTIL.

Define Count-controlled Iteration in programming constructs

Iteration that is repeated a given number of times, often using a loop like 'for i in range(0,10):'.

What is Condition-controlled Iteration in programming constructs?

Iteration that continues until a given condition is met, often using a loop like 'while i <= 20:'.

Describe recursion in programming.

Recursion is a programming construct where a subroutine calls itself until a stopping condition is met.

How does recursion differ from iteration in programming?

Recursion and iteration produce the same result, but recursion is more suited for certain problems and can be represented in fewer lines of code.

Define stopping condition in recursion.

Stopping condition in recursion is the criteria that, once met, stops the recursive calls.

Do recursive subroutines require a clearly defined stopping condition?

Yes, recursive subroutines must have a clearly defined stopping condition to avoid infinite loops.

Describe the creation of stack frames in recursion.

Each time a function calls itself recursively, a new stack frame is created within the call stack to store parameters, local variables, and return addresses.

What is tail recursion?

Tail recursion is a form of recursion that is implemented in a more memory-efficient way, requiring less stack space.

Define base case in recursion.

Base case in recursion is the condition that, when met, stops the recursive calls and starts the unwinding process.

How can a stack overflow occur in recursion?

A stack overflow can occur in recursion when the call stack runs out of memory due to excessive recursive calls.

Describe the disadvantage of recursion in terms of memory usage.

Recursion is inefficient in memory usage and can lead to a stack overflow if too many recursive calls are made.

What is the biggest danger associated with excessive recursion calls?

The biggest danger is a stack overflow, which can cause the program to crash.

How does recursion unwinding occur?

Recursion unwinding happens when the base case is reached, and information from the call stack is popped off.

Do recursive functions like factorial naturally exhibit recursion?

Yes, functions like factorial are naturally recursive due to their repetitive nature.

Define the concept of a call stack in recursion.

A call stack is a data structure that stores information about the active subroutines in a program during its execution.

How does recursion help in reducing the likelihood of errors in code?

Recursion can reduce errors by representing certain problems in fewer lines of code, making them easier to understand and maintain.

What is the advantage of using recursion for certain problems?

Recursion can represent problems in fewer lines of code, making them less error-prone and easier to understand.

Describe the process of tail recursion in programming.

Tail recursion is a form of recursion that optimizes memory usage by reusing the same stack frame for each recursive call.

Describe the difference between global and local variables in programming.

Global variables can be accessed across the whole program, while local variables have limited scope and can only be accessed within the block of code in which they were defined.

How does using local variables contribute to good programming practice?

Using local variables ensures that subroutines are self-contained, with no risk of variables being affected by code outside of the subroutine.

Define modularity in programming and its significance.

Modularity is the technique of splitting large programs into smaller, self-contained modules. It is crucial for making problems easier to understand, divide tasks among a team, and simplify testing and maintenance processes.

What is the top-down approach in modular programming?

The top-down approach involves breaking down a problem into sub-problems until each can be represented as an individual, self-contained blackbox that performs a specific task.

How does the presence of a local variable and a global variable with the same name affect the program?

The local variable takes precedence over the global variable if they share the same name within a subroutine.

Describe stepwise refinement in programming.

Stepwise refinement is a process where a complex problem is broken down into smaller, more manageable modules or subroutines.

Define subroutines in programming.

Subroutines are named blocks of code that can be categorized as functions or procedures, used to perform specific tasks.

How are procedures and functions different in programming?

Procedures do not have to return a value, while functions must always return a value.

Do procedures or functions return multiple values in programming?

Procedures can return multiple values, whereas functions must return a single value.

Describe the use of parameters in procedures and functions.

Procedures are typically given data as parameters for manipulation, while functions commonly make use of local variables.

Define passing by value in programming.

Passing by value means a copy of the value is passed to the subroutine, and changes made to the parameter do not affect the original value outside the subroutine.

Define passing by reference in programming.

Passing by reference means the address of the parameter is given to the subroutine, allowing the value of the parameter to be updated at that address.

Describe the function isEven(number) provided in the content.

The function isEven(number) checks if a given number is even, returning True if it is and False if it is not.

How are parameters typically assumed to be passed in exam questions?

In exam questions, parameters are usually assumed to be passed by value unless specified otherwise.

Describe what an IDE is and its purpose.

An IDE, or Integrated Development Environment, is a program that provides a set of to assist programmers in writing, developing, and debugging code.

Do IDEs allow users to monitor the effect of each individual line of code? If so, how?

Yes, IDEs allow users to monitor the effect of each individual line of code by using the 'Stepping' feature, which executes a single line at a time.

Define 'Variable watch' in the context of IDEs.

Variable watch is a feature in IDEs that allows users to observe how the contents of a variable change in real-time through the execution of a program.

How can breakpoints be helpful in debugging code within an IDE?

Breakpoints in IDEs allow users to set a point in the program at which the program will stop, helping to pinpoint where an error is occurring.

Describe the purpose of a source code editor in an IDE.

A source code editor in an IDE aims to make the coding process easier by providing features such as autocompletion, indentation, syntax highlighting, and automatic bracket completion.

What are some examples of IDEs mentioned in the content?

Examples of IDEs include PyCharm, Eclipse, IDLE, and Microsoft Visual Studio.

How do debugging tools in IDEs assist programmers?

Debugging tools in IDEs provide run-time detection of errors with guidance on where in the code they are likely to have occurred through line numbers and highlighting.

Describe the concept of a class in object-oriented programming.

A class is a template for an object that defines the state and behavior of an object.

What are attributes in object-oriented programming?

Attributes give an object's properties.

Define behavior in the context of object-oriented programming.

Behavior is defined by the methods associated with a class, describing the actions it can perform.

How are objects created in object-oriented programming?

Objects are created through a process called instantiation.

Explain the concept of encapsulation in object-oriented programming.

Encapsulation is when attributes are declared as private and can only be altered by public methods, protecting data from being accidentally edited by other parts of the program.

What is the purpose of encapsulation in programming?

Encapsulation is used to implement the principle of information hiding, making programs less complex by protecting data.

Describe the relationship between classes and objects in object-oriented programming.

An object is a particular instance of a class, and a class can be used to create multiple objects with the same set of attributes and methods.

What is the significance of top-down design in programming?

Top-down design implements the principle of encapsulation, with each module designed to be self-contained.

Describe what makes a problem solvable by computational methods.

Features that indicate a problem can be solved computationally include having inputs, outputs, and calculations, being solvable within a finite time, and being computable by algorithms.

Define computable problems in the context of computational methods.

Computable problems are those that can be solved within a realistic amount of time using algorithms.

How can breakthroughs in technology impact the solvability of problems computationally?

Advancements in technology have made it possible to solve more problems computationally than before by improving processing power, speed, and memory.

Do stakeholders play a role in problem recognition for computational problem-solving?

Yes, stakeholders define requirements for the finished product, aiding in clearly identifying the problem and system requirements.

Describe the concept of problem decomposition in computational problem-solving.

Problem decomposition involves breaking down a problem into smaller subproblems, making it more manageable and understandable.

How does problem decomposition aim to reduce complexity in computational problem-solving?

By breaking a problem into smaller sections, problem decomposition makes it easier to understand and implement, potentially utilizing pre-coded modules or libraries.

Define system requirements in the context of computational problem-solving.

System requirements are specifications derived from stakeholders' needs, strengths and weaknesses analysis, and data considerations for solving a problem computationally.

Describe the benefits of decomposition in project management.

Decomposition makes the project easier to manage by allowing different software development teams to work on separate sections of the code based on their expertise.

How does decomposition enable faster project delivery?

Decomposition enables multiple parts of the project to be developed in parallel, speeding up the project delivery process.

Define 'divide and conquer' in the context of problem-solving.

Divide and conquer is a problem-solving technique that involves breaking down a problem into three stages: divide, conquer, and merge.

What is the 'Divide' stage in the 'divide and conquer' technique?

The 'Divide' stage involves halving the size of the problem with every iteration.

How is the 'Conquer' stage typically carried out in 'divide and conquer'?

The 'Conquer' stage is often solved recursively, addressing each individual subproblem.

Explain the 'Merge' stage in the 'divide and conquer' technique.

The 'Merge' stage involves recombining the solutions to the subproblems to form the final solution to the problem.

Describe a common use of divide and conquer in binary search.

In binary search, the middle value of a sorted list is compared to the value being searched. Depending on the comparison result, either the upper or lower half of the list is discarded and the process is repeated recursively.

Define 'Decrease and Conquer' technique.

Decrease and Conquer is a problem-solving approach where the problem is reduced by less than half in each iteration, similar to divide and conquer.

How does divide and conquer simplify complex problems?

By halving the problem size with each iteration, divide and conquer greatly simplifies very complex problems.

Do quick sort and merge sort utilize divide and conquer?

Yes, quick sort and merge sort are sorting algorithms that apply the divide and conquer principle.

Describe the advantage of using divide and conquer in problem-solving.

The size of the problem is halved with each iteration, leading to a significant reduction in solving time as the problem size grows.

What is the time complexity of algorithms using divide and conquer?

The time complexity is O(logn) as the number of recursive calls halves with each iteration.

How does representational abstraction simplify problem-solving?

Representational abstraction removes excessive details to simplify a problem, allowing focus on core aspects and reuse of pre-programmed modules.

What challenges do recursive functions, including divide and conquer, face?

Recursive functions, like divide and conquer, can lead to stack overflow and make large programs difficult to trace.

Define 'stack overflow' in the context of recursive functions.

Stack overflow occurs when the call stack exceeds its memory limit, leading to program crashes.

How does abstraction help programmers in problem-solving?

Abstraction allows programmers to focus on essential aspects of a solution by removing unnecessary details and leveraging pre-existing solutions.

Describe the concept of abstraction by generalization in project management.

Abstraction by generalization involves grouping together different sections of a problem with similar underlying functionality to simplify coding and promote reusability.

Define backtracking as a problem-solving technique in computer science.

Backtracking is a methodical algorithmic approach that involves visiting each path to build a solution, backtracking to previous stages if an invalid path is encountered.

How is data mining used in software applications?

Data mining is used to identify patterns or outliers in large sets of data, helping to spot trends, correlations, and make predictions for future business and marketing decisions.

Do levels of abstraction help in managing large, complex projects?

Yes, levels of abstraction allow projects to be split into simpler parts, making them more manageable by hiding details of other layers and enabling different teams to work on individual components.

Describe the role of abstract thinking in representing real-world entities computationally.

Abstract thinking is required to represent real-world entities using computational elements like tables and variables once a problem has been abstracted into levels.

How does backtracking work in problem-solving algorithms?

Backtracking involves visiting each path methodically and building a solution based on correct paths, backtracking to previous stages if an invalid path is encountered.

What is the purpose of depth-first graph traversals in backtracking?

Depth-first graph traversals are an example of backtracking used to solve problems by visiting each path and returning back to the most recent stage with multiple path choices.

Define data mining and its application in handling big data.

Data mining is a technique to identify patterns in large data sets, collected from various sources, to spot trends, correlations, and make predictions for business and marketing decisions.

Describe the use of data mining in revealing insights about people's shopping habits and preferences.

Data mining is used to uncover insights about individuals' shopping behaviors and preferences based on their personal information, which can then be utilized for marketing strategies.

Define heuristics in problem-solving.

Heuristics are non-optimal, 'rule-of-thumb' approaches used to find approximate solutions to complex problems when the standard solution is too time-consuming or resource-intensive.

How does the GDPR impact data handling within the EU?

The GDPR mandates that all data held and processed by organizations within the EU must adhere to specific rules and regulations regarding data protection.

Explain the purpose of performance modeling.

Performance modeling aims to eliminate the need for actual performance testing by offering mathematical methods to assess how a system will perform under various loads and operating systems.

What is the benefit of pipelining in project delivery?

Pipelining allows for faster project delivery by breaking down modules into individual tasks that can be developed simultaneously, similar to a production line.

Describe the purpose of data visualization.

Data visualization is used to present data in a way that is easier to understand, helping to identify trends that may not be obvious.

What are some common ways data can be represented through visualization?

Data can be represented as graphs, trees, charts, and tables.

How is data visualization used by businesses?

Businesses use data visualization to identify patterns that can inform business decisions.

Define data visualization.

Data visualization is the presentation of data in a visual format to aid in understanding and identifying trends.

What is the significance of data visualization in analyzing statistical data?

Data visualization helps in identifying trends in statistical data that may not be apparent otherwise.