DS OEP

oep.txt

/*Meeting Management System using single linked list
Data Structures OEP
Topic - Singly Linked List
Author : Akshay Ashok , Anuj Jain , Jainal Gosaliya
*/
/*----------------------------------------------------------------------------*/
/* Define libraries to be included */
#include <stdio.h>
#include <malloc.h>
#include <string.h>
#include <ctype.h>
/*----------------------------------------------------------------------------*/
/* Define Functions*/
void clearInput(void);
void addNewMeeting(void);
void listAll(void);
void deleteMeeting(void);
void modifyMeeting(void);
int findMeeting(void);
int prompt(void);
int findnum (int);
/*----------------------------------------------------------------------------*/
/* Define Structures*/
typedef struct Meeting {   
    int number;        /*unique account number*/
    char name[20];     /*contains name*/  
    char time[15];    /*contains time number*/
    char venue[20];           /*contains venue address*/
    struct Meeting *next; /*next is used to navigate through structures.*/ 
    int count;     /*count is used to input comments into array*/    
    } Meeting;
Meeting *firstc,*currentc,*newc; /*pointers*/
/* firstc is used to point to first record in list
currentc points to current record in list
newc contains address of new structure/node 
*/
int cnum = 0; /*gives unique account numbers*/
/*----------------------------------------------------------------------------*/
/* Main Function */
int main()
{
    
    char ch;
    firstc = NULL;
     
    do
    {
	
        puts("\nWelcome To The Meeting Database");/* print menu messages*/
        puts("-- -----------------------------");
        puts("1 - Add a new Meeting");     
        puts("2 - Delete Meeting");          
        puts("3 - List all Meetings");       
        puts("-- -----------------------------");
        puts("Q - Save and quit\n");         
        printf("\tYour choice:");            
        ch = getchar();
	    ch = toupper(ch);/*changes user input case to upper case*/
        switch(ch)     /*stores in ch variable.*/
        {
        case '1':
            puts("Add a new Meeting\n");
            addNewMeeting();//call addNewMeeting function 
            break;
	    case '2':
            puts("Delete a Meeting\n");
            deleteMeeting();
            break;
	    case '3':
            puts("List all Meetings\n");
            listAll();
            break;
	    case 'Q':
            puts("Save and quit\n");
            default:
            break;
        }
    }
    while(ch != 'Q');

    
    
    
}
/*----------------------------------------------------------------------------*/
void addNewMeeting(void) /* add new Meeting function*/
{
    newc = (struct Meeting *)malloc(sizeof(struct Meeting)); 
    /*allocates memory for new structure.*/
/*
 * Checks to see whether this is the first record in file
 * If so, then all pointers are initialized to this record,
 */
    if(firstc==NULL)
        firstc = currentc = newc;
/* 
 * if not, end of structure list is obtained
 */
    else
    {
        currentc = firstc;      /* make the first record the current one*/ 
                                
        while(currentc->next != NULL)currentc = currentc->next;
                                /* and loop through all records*/ 
        currentc->next = newc;  /* pointer to next node */
        currentc = newc;        /* make current record the new one*/ 
    }
/* update the structure */
    cnum++;
    printf("%27s: %5i\n","Acount number",cnum);
    currentc->number = cnum;    /*cnum is used to give unique account numbers*/
    
    printf("%27s: ","Enter Meeting name");
    gets(currentc->name);
    gets(currentc->name);
    printf("%27s: ","Enter Meeting time number");
    gets(currentc->time);
    printf("%27s: ","Enter Meeting venue");
    gets(currentc->venue);
    printf("Meeting added!");
    currentc->count=0;
/* 
 * gives the new record a NULL pointer
 * to show it's the last record:
 */
    currentc->next = NULL;
}
/*----------------------------------------------------------------------------*/
void listAll(void) /* list all Meetings function*/
{
    if(firstc==NULL)
        puts("There are no Meetings to display! Enjoy your day"); /*prints message*/
        
    else
    {
	    printf("%6s %-20s %-15s %-15s\n","Acct#","Name","time","venue");
        puts("------ -------------------- ------------- -------------------");           
                            /*prints table titles*/
        currentc=firstc;
        
        do
        {
        
                printf("%6d: %-20s %-15s %-20s\n",\
                currentc->number,\
                currentc->name,\
                currentc->time,\
                currentc->venue); 
                /*prints values of number, name, time and venue*/
       }
        while((currentc=currentc->next) != NULL);
    }
}
/*----------------------------------------------------------------------------*/
void deleteMeeting(void)     /*delete Meeting function */          
{
    int record;
    struct Meeting *previousa;
    if(firstc==NULL)
    {
        puts("There are no Meetings to delete!, Don't Take too much stress");
	return;
    }
    
    listAll();		/* show all records*/  
    printf("Enter Meeting account number to delete: ");
    scanf("%d",&record);
    currentc = firstc;
    
    while(currentc != NULL)
    {
        if(currentc->number == record)
	{
	    if(currentc == firstc)	/*if record to be deleted is the first record*/
		firstc=currentc->next; /*reset firstc to point at next record as first*/
	    else
		previousa->next = currentc->next;/*previous pointer used if record*/ 
                                         /*to delete is not the first*/
        free(currentc); /*frees memory <deletes>*/
	    printf("Meeting %d deleted!\n",record);
	    return;
	}
	
	else
	{
        previousa = currentc;
	    currentc = currentc->next;
	}
    }
    printf("Meeting %d not found!\n",record);
 }
/*----------------------------------------------------------------------------*/

/*----------------------------------------------------------------------------*/
/* END OF PROGRAM */