deleting structs in an array and sorting the array of structs[ascending]..

This is a discussion on deleting structs in an array and sorting the array of structs[ascending].. within the C Programming forums, part of the General Programming Boards category; here is my code and i have some questions.... 1.) any suggestions how would i delete accounts in such a ...

  1. #1
    Registered User
    Join Date
    Mar 2009
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    39

    deleting structs in an array and sorting the array of structs[ascending]..

    here is my code and i have some questions....

    1.) any suggestions how would i delete accounts in such a way that if i delete one, then that empty slot is immediately occupied by accounts on its right [if there are any]...?

    2.)i want to sort my array of struct [ascending] according to every stud's student number... where should i implement this sorting?
    a.) whenever i create an account [to find a free slot AND a slot where the accnt fits[ascending]]?
    b.) upon displaying the accounts? [i.e i sort 1st before displaying]

    and which is easier and less complicated? a or b?

    thanks....

    Code:
    #include <stdio.h>
    #include <string.h>
    
    typedef struct student_profile{
    	long long int stud_num;
    	char name[50];
    	char bday[50];
    	char course[50];
    	} STUDENT;
    
    void login(char username[], char password[]);
    char admin(void);
    	void add_student(STUDENT array[20]);
    	void display_students(STUDENT array[20]);
    	void modify_student(STUDENT array[20]);
    	void search_student(STUDENT array[20]);
    	//void delete_student(STUDENT array[20]);
    	void delete_all(STUDENT array[20]);
    
    //*******************************************************************
    
    int main(void)
    {
    	STUDENT array[20];
    	char username[50];
    	char password[50];
    	char option;
    	int i;
    
    	for(i = 0; i < 20; i++)
    	{
    		array[i].stud_num = 0;
    	}
    
    	clrscr();
    
    	while(strcmp(username,"quit") != 0 || strcmp(password,"quit") != 0)
    	{
    
    	login(username, password);
    
    
    	if(strcmp(username, "ADMIN") == 0 && strcmp(password, "admin") == 0)
    	{
    		option = '0';
    
    		while(option != 'x')
    		{
    			option = admin();
    			switch(option)
    			{
    				case '1' :
    				{
    					gotoxy(14,48); printf("Redirecting to [Add Student] Function --->...");
    					getche();
    					add_student(array);
    					break;
    				}				//end of case '1'
    
    				case '2' :
    				{
    					gotoxy(14,48); printf("Redirecting to [Modify Student Account] Function --->...");
    					getche();
    					modify_student(array);
    					break;
    				}				//end of case '2'
    
    				/*case '3' :
    				{
    					gotoxy(14,48); printf("Redirecting to [Delete Student Account] Function --->...");
    					getche();
    					delete_all(array);
    					break;
    				}*/				//end of case '3'
    
    				case '4' :
    				{
    					gotoxy(14,48); printf("Redirecting to [Search Student Account] Function --->...");
    					getche();
    					search_student(array);
    					break;
    				}				//end of case '4'
    
    				case '5' :
    				{
    					gotoxy(14,48); printf("Redirecting to [Display all Accounts] Function --->...");
    					getche();
    					display_students(array);
    					break;
    				}				//end of case '5'
    
    				case '6' :
    				{
    					gotoxy(14,48); printf("Redirecting to [Delete all Accounts] Function --->...");
    					getche();
    					delete_all(array);
    					break;
    				}				//end of case '6'
    
    
    				case '7' :
    				{
    					gotoxy(14,50); printf("Logging out...");
    					getche();
    					option = 'x';
    					break;
    				}				//end of case '7'
    
    				case 'x' :
    				{	gotoxy(14,48); printf("Terminating Program...");
    					getche();
    					return 0;
    				}				//end of case '8'
    
    				default :
    				{	printf("\n\nInvalid option");
    				}  				//end of default
    			}					//end of switch
    		}						//end of while(option != '6')
    	}							//end of while(strcmp...)
    
    	/*else if(ang account kay student)
    	{
    	}*/
    
    	else
    	{
    		if(strcmp(username,"quit") != 0 && strcmp(password,"quit") != 0)
    		{
    			gotoxy(19,30); printf("Invalid username or password.");
    		}
    
    	}
    	}							//end of super big loop! XD haha
    
    	gotoxy(19,31); printf("Terminating Program...");
    	getche();
    	return 0;
    }
    
    //*******************************************************************
    
    void login(char username[], char password[])
    {
    	clrscr();
    
    	gotoxy(19,5);  printf("********* ********    ***     *** *********");
    	gotoxy(19,6);  printf("**    ***  **    ***   ***   ***  **    ***");
    	gotoxy(19,7);  printf("**     **  **     ***  ***   ***  **     **");
    	gotoxy(19,8);  printf("***        **    ***   **** ****  ***      ");
    	gotoxy(19,9);  printf("********   *******     ** *** **  ******** ");
    	gotoxy(19,10); printf(" ********  **    ***   ** *** **   ********");
    	gotoxy(19,11); printf("      ***  **     **   **  *  **        ***");
    	gotoxy(19,12); printf("**     **  **     **   **     **  **     **");
    	gotoxy(19,13); printf("***    **  **     **   **     **  ***    **");
    	gotoxy(19,14); printf("********* ***     *** ****   **** *********");
    	gotoxy(45,40); printf("Just type 'quit' as username");
    	gotoxy(45,41); printf("and 'quit' also as password");
    	gotoxy(45,42); printf("to terminate program.");
    	gotoxy(45,45); printf("Student Record Management System");
    	gotoxy(19,22); printf("Enter username:");
    	gotoxy(35,22); gets(username);
    	gotoxy(19,24); printf("Enter password:");
    	gotoxy(35,24); gets(password);
    }
    
    //*******************************************************************
    
    char admin(void)
    {
    	char option;
    
    	clrscr();
    
    	gotoxy(14,2); printf("===================================================");
    	gotoxy(14,4); printf("               Administrator's Menu");
    	gotoxy(14,6); printf("===================================================");
    
    	gotoxy(14,10); printf("[1]     ---     Add a Student");
    	gotoxy(14,12); printf("[2]     ---     Modify a Student Account.");
    	gotoxy(14,14); printf("[3]     ---     Delete a Student Account.");
    	gotoxy(14,16); printf("[4]     ---     Search a Student Account.");
    	gotoxy(14,18); printf("[5]     ---     Display all Student Account Entries.");
    	gotoxy(14,20); printf("[6]     ---     Delete all Student Account Entries.");
    	gotoxy(14,22); printf("[7]     ---     Logout");
    	gotoxy(14,24); printf("[x]     ---     Terminate Program.");
    
    	gotoxy(14,28); printf("===================================================");
    
    	gotoxy(14,32); printf("Please choose the task you want to perform.");
    	gotoxy(14,34); scanf("%c", &option);
    
    	return option;
    }
    
    //*******************************************************************
    
    void add_student(STUDENT array[20])
    {
    	int i = 0;
    	int empty;
    	char opt = 'y';
    
    	while(opt == 'y' && i < 19){
    	for(i = 0; i < 20; i++)
    	{
    		if(array[i].stud_num == 0)
    		{
    			empty = i;
    			break;
    		}
    	}
    
    	clrscr();
    
    	if(i >= 19)
    	{
    		gotoxy(14,2);  printf("===================================================");
    		gotoxy(14,4);  printf("            Enter account information");
    		gotoxy(14,6);  printf("===================================================");
    		gotoxy(14,22); printf("===================================================");
    		gotoxy(14,32); printf("There are currently no free slots.");
    		gotoxy(14,26); printf("===================================================");
    
    	}
    
    	else
    	{
    		gotoxy(14,2);  printf("===================================================");
    		gotoxy(14,4);  printf("            Enter account information");
    		gotoxy(14,6);  printf("===================================================");
    		gotoxy(14,22); printf("===================================================");
    		gotoxy(14,26); printf("===================================================");
    
    		gotoxy(16,9);  printf("Student Number  [Username]:");
    		gotoxy(16,13); printf("Name:");
    		gotoxy(16,15); printf("Birthdate:");
    		gotoxy(16,17); printf("Course:");
    
    		gotoxy(32,11); scanf("%lld", &array[empty].stud_num);
    		gotoxy(32,13); gets(array[empty].name);					//try unya ang fgets(); if sakto na...
    		gotoxy(32,13); gets(array[empty].name);
    		gotoxy(32,15); gets(array[empty].bday);
    		gotoxy(32,17); gets(array[empty].course);
    
    		gotoxy(14,24); printf("       --- Account successfully created ---");
    
    		if(i >= 19)
    		{
    			clrscr();
    			gotoxy(14,2);  printf("===================================================");
    			gotoxy(14,4);  printf("            Enter account information");
    			gotoxy(14,6);  printf("===================================================");
    			gotoxy(14,22); printf("===================================================");
    			gotoxy(14,24); printf("There are currently no free slots.");
    			gotoxy(14,26); printf("===================================================");
    
    		}
    
    		else
    		{
    			gotoxy(14,32); printf("Do you want to enter another account?");
    			gotoxy(14,33); printf("[y for yes, else no]");
    			gotoxy(14,35); opt = getche();
    		}
    	}
    	} // end of while loop
    
    	gotoxy(14,48); printf("<--- Redirecting to the Administrator's page...");
    	getche();
    }
    
    //*******************************************************************
    
    void display_students(STUDENT array[20])
    {
    	int i, j;
    	long long int temp;
    
    	clrscr();
    
    	gotoxy(6,2);  printf("=====================================================================");
    	gotoxy(6,4);  printf("STUDENT NUMBER");
    	gotoxy(25,4); printf("NAME");
    	gotoxy(45,4); printf("BIRTHDATE");
    	gotoxy(65,4); printf("COURSE");
    	gotoxy(6,6);  printf("=====================================================================");
    
    	//for(i = 1; i <= 20 - 1; i++)										/*passes*/
    	//{
    	//    for(j = 0; j <=  20-2; j++)  									/*one pass*/
    	 //   {
    	//        if(array[j].stud_num > array[j + 1].stud_num)    			/*one comparison*/
    	//        {
    	//			temp = array[j].stud_num;        						/*one swap*/
    	//            array[j].stud_num = array[j + 1].stud_num;
    	//          	array[j + 1].stud_num = temp;
            //    }
    	//	}
    	//}
    
    	for(j = 10, i = 0; array[i].stud_num != 0; j++, i++)
    	{
    		if(array[i].stud_num > 0)
    		{
    			gotoxy(6,j);  printf("%lld", array[i].stud_num);
    			gotoxy(25,j); puts(array[i].name);
    			gotoxy(45,j); puts(array[i].bday);
    			gotoxy(65,j); puts(array[i].course);
    		}
    	}
    
    	gotoxy(6,j+2); printf("\=====================================================================");
    	gotoxy(6,48);  printf("<----- Redirecting to the Administrator's Page...");
    	getche();
    }
    
    //*******************************************************************
    
    void modify_student(STUDENT array[20])
    {
    	int i;
    	long long int stud_num;
    
    	clrscr();
    	printf("\n\nPlease enter the student number of the account to be modified:\n\n");
    	scanf("%lld", &stud_num);
    	printf("\n\nSearching Student Account with Student Number %lld...", stud_num);
    
    	for(i = 0; i < 20; i++)
    	{
    		if(stud_num == array[i].stud_num)
    			break;
    	}
    
    	if(i >= 19)
    	{
    		printf("\n\nThe given student number did not match any of the existing accounts.\n");
    		printf("\n\nRedirecting to Administrator's Page...");
    		getche();
    	}
    
    	else
    	{
    		gotoxy(1,10);  printf("=====================================================");
    		gotoxy(1,12);  printf("Modifying the account of %s", array[i].name);
    		gotoxy(1,14);  printf("=====================================================");
    		gotoxy(1,16);  printf("Current Student Number: %lld", array[i].stud_num);
    		gotoxy(40,16); printf("New Student Number:");
    		scanf("%lld", &array[i].stud_num);
    		gotoxy(1,18);  printf("Current Name: %s", array[i].name);
    		gotoxy(40,18); printf("New Name: ");
    		gets(array[i].name);
    		gets(array[i].name);
    		gotoxy(1,20);  printf("Current Birthdate: %s", array[i].bday);
    		gotoxy(40,20); printf("New birthdate: ");
    		gets(array[i].bday);
    		gotoxy(1,22);  printf("Current Course: %s", array[i].course);
    		gotoxy(40,22); printf("New Course: ");
    		gets(array[i].course);
    
    		printf("\n\n=====================================================");
    		printf("\n\nStudent account modified...");
    		printf("\n\nRedirecting to Administrator's Page...");
    		printf("\n\n=====================================================");
    		getche();
    	}
    }
    
    //*******************************************************************
    
    /*void delete_student(STUDENT array[20])
    {
    	printf("\n\nEnter the ");
    
    }*/
    
    //*******************************************************************
    
    void delete_all(STUDENT array[20])
    {
    	int i;
    	char option;
    
    	clrscr();
    	gotoxy(14,2);  printf("===================================================");
    	gotoxy(14,4);  printf("       Delete All Student Accounts Function        ");
    	gotoxy(14,6);  printf("===================================================");
    	gotoxy(14,24); printf("===================================================");
    	gotoxy(14,28); printf("===================================================");
    	gotoxy(14,12); printf("Are you sure you want to delete all student accounts?");
    	gotoxy(14,14); printf("press 'y' for yes, else a no...");
    	gotoxy(20,18); option = getche();
    
    	if(option == 'y')
    	{
    		for(i = 0; i < 20; i++)
    		{
    			array[i].stud_num = 0;
    			strcpy(array[i].name, "");
    			strcpy(array[i].bday, "");
    			strcpy(array[i].course, "");
    		}
    
    		gotoxy(14,26); printf("        Deletion of All Accounts Successful        ");
    	}
    
    	else
    	{
    		gotoxy(14,26); printf("                     Aborted                       ");
    	}
    
    
    	gotoxy(14,48); printf("<-- Redirecting to Administrator's Page...");
    	getche();
    }
    
    //*******************************************************************
    
    void search_student(STUDENT array[20])
    {
    	long long int stud_num;
    	int i;
    
    	clrscr();
    	gotoxy(14,2);  printf("===================================================");
    	gotoxy(14,4);  printf("             Search Student Function               ");
    	gotoxy(14,6);  printf("===================================================");
    	gotoxy(14,10); printf("Enter Student Number:");
    	gotoxy(40,10); scanf("%lld", &stud_num);
    	gotoxy(14,14); printf("Searching Account with Student Number %lld..", stud_num);
    
    	for(i = 0; i < 20; i++)
    	{
    		if(stud_num == array[i].stud_num)
    			break;
    	}
    
    	if(i >= 19)
    	{
    		gotoxy(14,18); printf("The given student number did not match");
    		gotoxy(14,20); printf("any of the existing accounts.");
    		getche();
    	}
    
    	else
    	{
    		gotoxy(14,18); printf("Student Number:");
    		gotoxy(35,18); printf("%lld", array[i].stud_num);
    		gotoxy(14,20); printf("Name");
    		gotoxy(35,20); printf("%s", array[i].name);
    		gotoxy(14,22); printf("Birthdate:");
    		gotoxy(35,22); printf("%s", array[i].bday);
    		gotoxy(14,24); printf("Course:");
    		gotoxy(35,24); printf("%s", array[i].course);
    	}
    
    	gotoxy(14,48); printf("<-- Redirecting to Administrator's Page...");
    	getche();
    }
    
    //*******************************************************************

  2. #2
    Kernel hacker
    Join Date
    Jul 2007
    Location
    Farncombe, Surrey, England
    Posts
    15,677
    I would do the sorting only when the user request a list. That way there is less messing about keeping the list sorted at all times.

    --
    Mats
    Compilers can produce warnings - make the compiler programmers happy: Use them!
    Please don't PM me for help - and no, I don't do help over instant messengers.

  3. #3
    Registered User
    Join Date
    Mar 2009
    Posts
    39
    ok sir thanks a lot...
    ill do my coding now...
    consultation time later... please?
    thanks =)

  4. #4
    Algorithm Dissector iMalc's Avatar
    Join Date
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    Location
    New Zealand
    Posts
    6,295
    Both options are fairly easy and uncomplicated, but using qsort to sort before printing would probably be least code.
    My homepage
    Advice: Take only as directed - If symptoms persist, please see your debugger

    Linus Torvalds: "But it clearly is the only right way. The fact that everybody else does it some other way only means that they are wrong"

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