Computer Science Answer Note #13

Question 1 Consider the following code snippet: int* ptr = NULL; *ptr = 100; Which signal will the kernel send to the process that is trying to execute the code snippet above? SIGKILL SIGINT SIGSEGV SIGFPE SIGABRT Answer Based on the given code snippet, the kernel will send the signal SIGSEGV (Segmentation Fault) to the process. SIGSEGV is a signal that is sent to a process when it tries to access a memory location that is not allowed or does not exist. This signal is triggered when a process tries to access memory outside of its allocated space, or when it tries to access memory that is marked as read-only. In the given code snippet, the pointer is pointing to NULL, which is a memory address that is not allowed to be accessed. Therefore, when the process tries to assign a value (100) to that memory address, the kernel will send the SIGSEGV signal to the process. Question 2 akhil took two pointers one that points at the start of the string and the other at the end of the string. The characters are reversed one by one with the help of these two pointers.reverse all characters,build a flowchart and algorithm and write c code Answer First, we need to understand the concept of pointers in computer science. Pointers are variables that store the memory addresses of other variables. In this case, the two pointers will be used to keep track of the start and end of the string. By swapping the characters at these two positions, we can effectively reverse the string. Algorithm: 1. Take input for the string we want to reverse. 2. Assign two pointers to the start and end of the string. 3. Create a loop that continues till the pointers meet or cross each other. 4. Within the loop, swap the characters at the positions pointed by the pointers. 5. Increment the first pointer and decrement the second pointer. 6. When the loop ends, the string will be reversed. Flowchart: (See attached image) C Code: Question 3 5. Define a classes Person and it has attributes name, DOB, Address, Father name, Classname and use set function to give value and get function to show value. Create Object of the class. Answer The class Person can be defined as a template that represents a person with attributes such as name, date of birth, address, father's name, and class name. It can be used to store and manipulate data related to a particular person. To create a class Person, we can use the following syntax in C++: class Person { // Attributes string name; string dob; string address; string fatherName; string ClassName; // Setters void setName(string n) { name = n; } void setDOB(string d) { dob = d; } void setAddress(string a) { address = a; } void setFatherName(string f) { fatherName = f; } void setClassName(string c) { ClassName = c; } // Getters string getName() { return name; } string getDOB() { return dob; } string getAddress() { return address; } string getFatherName() { return fatherName; } string getClassName() { return ClassName; } }; In the above code, we have defined the class Person with its attributes and functions. The set functions are used to give values to the attributes while the get functions are used to show the values. To create an object of the class Person, we can use the following code: int main() { // Creating an object Person person1; // Setting values using set functions person1.setName("John"); person1.setDOB("01-01-2000"); person1.setAddress("123 Main St"); person1.setFatherName("David"); person1.setClassName("University Student"); // Getting values using get functions cout << "Name: " << person1.getName() << endl; cout << "Date of Birth: " << person1.getDOB() << endl; cout << "Address: " << person1.getAddress() << endl; cout << "Father& Question 4 Create a flowchart for Teacher's availability with slots for entire week in a tutoring application so that students can book a session with teachers Answer As a Masters student with high marks, one must understand the importance of a wellstructured and efficient flowchart. In this case, a flowchart for a tutoring application that allows students to book a session with teachers is essential to ensure a smooth and organized process for both students and teachers. To create an effective flowchart for this task, we must first understand the key components and functionalities of the tutoring application. This includes the availability of teachers, the scheduling of sessions, and the booking process for students. With this in mind, we can now proceed to design the flowchart using the appropriate symbols and guidelines. The first step in creating the flowchart would be to identify all the necessary inputs and outputs. Inputs may include the availability of teachers, booked sessions, and student requests. Outputs may include confirmed bookings, reminders, and cancellation requests. Once all the inputs and outputs are identified, we can begin designing the flowchart. The flowchart would start with the process of checking teacher availability for the entire week. This can be represented by a decision symbol, with a yes or no answer. If the answer is no, the flowchart would end, and the student would be informed that there are no available teachers for that week. If the answer is yes, the flowchart would proceed to the next step. Next, the flowchart would lead to the scheduling of sessions for each available teacher. This can be represented by a process symbol, with sub-processes for each day of the week. The sub-process for each day would include the available time slots for that particular day, as well as the number of students allowed per session. This sub-process would loop for each day of the week until all available sessions are scheduled. After the scheduling process is complete, the flowchart would lead to the booking process for students. This can be represented by an input/output symbol, with a sub-process for student requests. The student would enter their preferred day and time, and the flowchart would check for availability. If the requested slot is available, the flowchart would move to the confirmation process. If not, the student would be prompted to choose another available slot. Once the booking is confirmed, the flowchart would generate an output for the student and the teacher. This could include a confirmation email, reminder, or any other necessary information. If the student wishes to cancel the session, the flowchart would lead to the cancellation process, where the student can input their request and the flowchart would generate an output accordingly. Question 5 tokenization of Nigerian naira using homomorphic data encryption algorithm for a safe and inclusive banking in Nigeria Answer In recent years, there has been a growing interest in utilizing data encryption algorithms for secure and inclusive banking systems, especially in developing countries like Nigeria. One of the key challenges faced by financial institutions in Nigeria is the high rate of financial fraud and identity theft, which poses a threat to the stability and growth of the banking sector. Therefore, the use of data encryption algorithms, specifically homomorphic data encryption, can provide a solution to this challenge. Homomorphic data encryption is a form of data encryption that allows computations to be performed on encrypted data without the need for decryption. In other words, it allows for data to be securely processed while it remains in an encrypted form. This is particularly useful in a banking system, as it enables financial transactions to be performed without the risk of exposing sensitive data to potential hackers. In the context of Nigeria, the use of homomorphic data encryption can be applied to the tokenization of the Nigerian Naira, the country's official currency. Tokenization is the process of converting sensitive data, such as credit card numbers or currency, into a unique identifier, known as a token. By tokenizing the Naira, it will be possible to perform secure financial transactions without revealing any sensitive information. There are several advantages of using homomorphic data encryption for tokenization of the Nigerian Naira in the banking sector. Firstly, it provides an additional layer of security, making it difficult for hackers to intercept and access financial data. Secondly, it promotes financial inclusion by ensuring that sensitive data is not compromised, thereby building trust and confidence in the banking system. Thirdly, it can streamline financial transactions and improve efficiency, reducing the cost and time required for processing. Furthermore, homomorphic data encryption can facilitate secure mobile banking in Nigeria, which is becoming increasingly popular in the country. By tokenizing the Naira, users can securely perform financial transactions on their mobile devices without the risk of exposing their financial data. To implement this solution, financial institutions in Nigeria need to collaborate with experts in the field of data encryption and mobile technologies. They also need to adhere to strict security protocols and standards to ensure the effectiveness of the system. In conclusion, the tokenization of the Nigerian Naira using homomorphic data encryption can provide a safe and inclusive banking system in Nigeria. It is a promising solution that has the potential to address many challenges faced by the banking sector. By implementing this solution, financial institutions in Nigeria can not only enhance the security of their transactions but also contribute to the overall economic development of the country.