I need help in my homework in c language.

Question

1) Define a structure type called PersonCar of three fields: a person name (pName), a car model (cModel) two strings and a car price (price) a real number.

2) Declare pc an array of 4 PersonCars, c an integer number of registered cars in the system initially zero, and npc a pointer to struct PersonCar initially NULL that will point to a dynamically allocated array and represents the total cars registered or not in the system. These 3 variables pc, c, and npc are declared as global variables. Give the segment names where these variables are stored in.

3) In the main program, the user is requested to enter the number of cars to register less than or equal to 4. The user then enters his name and the car models and prices that will be stored in pc. The system can register many persons and their cars as long as there is a space in the system (only 4).

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Dr. Charbel Rahhal 2020 - 2021

4) Define a function float calculatePrice(struct PersonCar *p, char *name) that takes as parameters a pointer to a structure PersonCar and a person name, calculates and returns the total price of the registered cars for the given person.

5) Define a function void changeName(struct PersonCar *p, char *currentName, char *newName, char * gender) that changes the name of a person in the array of registered cars PersonCars p. If the person is a male then the current name becomes new name in p. If she is a female with a name starting with “Miss”, the function removes Miss from the name and adds her husband’s surname newName to the end the female’s name in p.

Example: “Miss Rose” and husband’s last name is “Miller” then her name becomes “Rose Miller”.

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Dr. Charbel Rahhal 2020 - 2021

6) Define a function struct PersonCar* changeTotalCars(void) that will be executed only if the total number of registered cars in the system c = 4, asks the system’s owner to enter an integer nnc > 4 and a new array of PersonCars of size nnc will be dynamically allocated in the system and its address is stored in variable npc previously declared in question 1). All the registered cars in array pc will be copied into npc. The function then asks the user to enter the number of cars to register in the system. If there is enough space in npc, the user name, cars models and prices will be entered and stored in npc otherwise it returns NULL.

7) A person sold his car so it will be removed (person name, car model, and price) from the system. Define a function struct PersonCar * deletePersonCar(char * persName, char * carModel) that deletes the car of model carModel for the person persName from the array npc after resizing it. The function will return a pointer to the new array. Remember to decrease the number of registers cars c by 1.

Example of calling this function: npc = deletePersonCar(“May”, “BMW”);

Answer 1

I can't do your homework for you, but I'll post similar answers so you get the idea.

1) A struct combines multiple member variables into a single record.

1. To add string information like names, I create character array fields, such as char hostname[21]. The number of entries in the array goes inside the square brackets. Make sure that number is big enough to include all values you would want to have in there, plus an extra null terminating character 0.
2. To add decimal numbers, I create float fields, such as float cost.

struct Computer {

char hostname[20];

float cost;

};

2) Here's an example of an array using the Computer struct again:

// This example array contains 10 Computer structs.

struct Computer computers[10];

// This variable indicates we have 0 Computers in use.

int computerCount = 0;

// Here's a pointer, set to NULL initially.

struct Computer* dynamicCars = NULL;

Programs consist of several segments, which are regions of memory that contain different kinds of data:

1. code - instructions
2. data - initialized global variables
3. read-only data - initialized read-only global variables and strings
4. stack - local variables
5. heap - dynamically allocated memory (allocated with malloc, calloc, etc.)
6. bss - uninitialized global variables

Which one do you think your global variables are stored in? Pay attention to whether they are initialized or not, and keep in mind that your instructor may not accept "bss" as an answer even if it's the best fit.

For question 3, here's an example program:

#include <stdio.h>

#include <stdlib.h>

struct Computer {

char hostname[20];

float cost;

};

// This example array contains 10 Computer structs.

struct Computer computers[10];

// This variable indicates we have 0 Computers in use.

int computerCount = 0;

int main(int argc, char** argv) {

printf("Enter number of computers: ");

scanf("%d", &computerCount);

// Handle case where there are more computers than

// the available storage space allows.

if (computerCount > 10) {

printf("Too many computers!\n");

exit(EXIT_FAILURE);

}

for (int index = 0; index < computerCount; index++) {

// Here's how to ask for a string as input:

printf("Enter the name of computer %d: ", index);

// The %20s placeholder reads up to 20 characters

// plus the null terminator.

scanf("%20s", computers[index].hostname);

// Here's how to ask for a float as input:

printf("Enter the cost of computer %d: ", index);

// Note that I use %f instead of %s or %d to

// read a float.

scanf("%f", computers[index].cost);

}

}

I hope that gives you a good start (without giving away the answers). Let me know if you'd like to book a session to get some more help!