Question

Q6. [40 MARKS] Write and document a complete C program to satisfy the following requirements. Given a sequential text file that has the following layout where each line is one record containing the following fields (separated by a single space): int player_id (a unique positive integer) string name (holds the full name in the form: firstname_lastname; each of first and last name cannot exceed 20 chars) float salary (weekly salary) The file may contain any number of records. Each record is in a separate line. You are asked to write a complete C program to include the following features: 1. Define a proper structure to accommodate the storage of the records in memory. (call the structure: player) 2. Design and declare all variables and functions as appropriate to do the processing as required for this program (You may use a minimum set of global variables whenever possible). 3. Write all necessary code to: a) Read the records from the input file (called "playerlist.dat") b) Sort all the records by the "last name" field in ascending order. (Hint: use insertion sort while reading; if two records have the same last name, use the first name to break the tie. No two records have the same full name) c) Display the results on the screen in descending order. d) Write your results back into the file "playerlist.dat" and thereby overriding its contents, and where the records are now stored in the file (the results in the file will be in ascending order as shown in the example below). Given the following sample sequential text file to illustrate: Sample contents of "playerlist.dat" before processing: 2 john doe 800.50 4 mary jane 1200.10 i britney spears 600.00 3 bob_spears 100.00 5 david letterman 700.30 Sample contents of "playerlist.dat" after processing (i.e. after executing the program): 2 john_doe 800.50 4 mary jane 1200.10 5 david letterman 700.30 3 bob spears 100.00 1 britney spears 600.00 Requirements: Your program should be able to handle a file with any number of records. Design an appropriate structure to handle the fields in the file as well as your programming technique. Write all functions necessary and explain the process of your technique (Write your algorithm clearly and document your code!) The full name is stored with an underscore character substituting the space character. When displayed on the screen however, the underscore character is replaced by a space character. You may assume that the records have a unique id. -

// includes [1 mark]

// structure definition [5 marks]

// global variables [2 marks]

// function prototypes [2 marks]

// main function (no menu required – just invoke the function calls to // satisfy the requested program sequence) [5 marks]

// Code all necessary functions [25 marks]

Answer 1

#include<string.h>
#include<stdio.h>
#include <stdlib.h>
struct player
{
unsigned int id;
char name[20];
char pName[20];
float salary;
struct player *next;
};

void ReadFile(struct player **);
void WriteFile(struct player *);
struct player * add_node(struct player *list, struct player *node);
void printReverse(struct player * head) ;

int main()
{
   struct player *head=NULL;
  
   ReadFile(&head);
   //insertionSort(head);
   WriteFile(head);
   printReverse(head) ;
   return 0;
}

void ReadFile(struct player **head)
{
   FILE * fp;
char * line = NULL;
size_t len = 0;
ssize_t read;
   struct player *temp, *iter=*head;
   fp = fopen("player.dat", "r");
if (fp == NULL)
return ;

while ((read = getline(&line, &len, fp)) != -1) {
temp = (struct player *) malloc(sizeof(struct player));
      
       sscanf(line, "%d %s %f", &temp->id, &temp->name, &temp->salary);
//       printf("Retrieved line of length %d %s %f:\n", temp->id, temp->name, temp->salary);
      
       processName(temp);
//       printf("check\n");
       *head = add_node(*head, temp);  

}
  
fclose(fp);
if (line)
free(line);
}

processName(struct player *temp)
{
   char first_name[20]={0};
   char last_name[20]={0};
  
   int i=0,j=0;
   //printf("%s\n",temp->name);
   while(temp->name[i] != '_' )
   {
       first_name[i] = temp->name[i];
       i++;
   }
   first_name[i]='\0';
   while(temp->name[i] !='\0')
   {
       last_name[j]=temp->name[i] ;
       i++;j++;
   }
   last_name[j]='\0';
  
  
   strcpy(temp->pName, last_name);
   strcat(temp->pName, first_name);
  
}

void WriteFile(struct player *head)
{
  
  
   char rp[100]={0};
   struct player *temp=head;
   FILE *outfile;
  
// open file for writing
outfile = fopen ("person.dat", "w");
if (outfile == NULL)
{
fprintf(stderr, "\nError opend file\n");
return;
  
}
  
  
   if(temp == NULL)
           printf("\nNo data\n");
   while(temp!=NULL)
   {
       fprintf(outfile, "%d %s %.2f\n",temp->id, temp->name, temp->salary);
      
   //   printf("%s\n", temp->pName);
       temp=temp->next;
   }
  
   fclose (outfile);
  
  
   remove("player.dat");
   rename("person.dat","player.dat");
}

struct player * add_node(struct player *list, struct player *node){
   struct player *prev, *next;
   if (!list) {
       list = node;
   }
   else {
       prev = NULL;
       next = list;
       while (next && strcmp((node)->pName, next->pName) >0 ){//compare_node(node,next)>0) {
           prev = next;
           next = next->next;
       }
       if (!next) {
           prev->next = node;
       }
       else {
           if (prev) {
               node->next = prev->next;
               prev->next = node;
           }
           else {
               node->next = list;
               list = node;
           }
       }
   }
   return list;
}

void printReverse(struct player * head)
{
// Base case
if (head == NULL)
return;
  
// print the list after head node
printReverse(head->next);
  
// After everything else is printed, print head
// cout << head->data << " ";
   printf("%d %s %.2f\n",head->id, head->name, head->salary);
}