Question

The question is about C Programming.

Can you give me an example in c, the requirements are:

The program need to provide users with the ability to create an account. An account should be a structure type variable containing: a username, a password.

Please provide more explains about some steps, and write in C.

Thank you!

Answer 1

Below is the desired C program, where we use linked list to create entry for new record.

#include<stdio.h>

struct account { //defining structure for account

char username[15];

char password[15]; //assuming username, password are 15 letters atmost

struct account *next; //pointer to next element in linked list

};

struct account *Root; //creating global pointer for root of linked list

//Now below function will take as input, the root of linked list and add a new account at the last entry of linked list

void add_account(struct account *root, char *uname, char *passwd)

{

struct account *temp;

if (root==NULL) //means linked list is empty

{

root = (struct account *) malloc (sizeof (struct account ));

strcpy (root->username, uname); //copy uname provided

strcpy (root->password, passwd); //copy passwd provided

root->next = NULL; //set next node to be NULL

return ; //Return from this function

}

else { //when linked list is not empty

temp = root; //initialize temp variable with root node

while (temp->next != NULL) //go to the last element of linked list

{

temp = temp->next; //proceed till the end of linked list

}

temp->next = (struct account *) malloc (sizeof (struct account)); //create space for new account

temp = temp->next; //now switch to new element and add entry

strcpy (temp->username, uname); //copy the username

strcpy(temp->password, passwd);// copy the password

temp->next = NULL; //set the next pointer of last element to NULL

return;

}

}

Please comment for any clarification.