Thread: 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();
}

//*******************************************************************