#include<stdio.h>
#include<conio.h>
#include<stdlib.h>
#include<string.h>

#define NAME 40
#define CLASS 10
#define SUBJ 5
#define NUM_REC 100

struct ST	{
		char name[NAME];
		char exam[CLASS];
		int marks[SUBJ];
		} ;  //end of structure

void showrec(ST *, int );
void addrec(ST *, int *);
void edit(ST *, int);
char lower(char );
int getchoice(char *);
int load(ST *, char *);
void save(ST *, char *, int);
void find(ST *, int );
void show1(ST , char *);
int total(ST );

void main(int argc, char  *argv[])
{
ST s[NUM_REC];
int cha,j=0;
if(!argv[1])
	{
	printf("\nUSAGE: drive:\...> MDB filename.mdb \n");
	exit(0);
	}

do { clrscr();
	printf("%s : Is this a N: New File or "
			"U: File to Update? ",argv[1]);
	cha=getche();
	cha=lower(cha);
   } while(cha!='n' && cha!='u') ;

if(cha=='u')
	{
	j=load(s, argv[1]);
	if(j==-1)
		{
		puts("\nBAD FILENAME!! IT DOES NOT EXIST!!");
		exit(1);
		}
	}
else if(cha=='n')
	while(cha!=27)
	{
	addrec(s, &j);
	if(j>NUM_REC-1)	break; //to break in case of XS rec.
	printf("\nPress ESC to stop, any other key to continue...");
	cha=getche();
	}

showchoices:
cha=getchoice(argv[1]);
if(cha==0)
	{
	printf("\nSave File? [yn] ");
	if(lower(getche())=='y')	save(s, argv[1], j);
	}
else if(cha==1)
	{
	save(s, argv[1], j);
	goto showchoices;
	}
else if(cha==2)
	{
	showrec(s,j);
	goto showchoices;
	}
else if(cha==3)
	{
	find(s,j);
	goto showchoices;
	}
else if(cha==4)
	{
	addrec(s, &j);
	goto showchoices;
	}
else if(cha==5)
	{
	edit(s, j);
	goto showchoices;
	}
else
	{
	putch(7);
	goto showchoices;
	}

{	// credits
puts("\n\nThanks for using this program. ");
puts("This program is (c) Hrishikeh M. 1998.");
puts("Please feel free to MODIFY it in any way you like :)");
}	// end of credits
}	// end of main()

int getchoice(char *filename)
{
clrscr();
printf("File %s is active... ",filename);
puts("\n");
puts("0: SAVE & EXIT");
puts("1: SAVE");
puts("2: LIST RECORDS");
puts("3: FIND ");
puts("4: ADD RECORD");
puts("5: EDIT RECORD");
int ch;
ch=getche();
ch-=0x30; // 30h is ascii 0
return ch;
}         // end of getchoice()

int load(ST *s, char *filename)
{
int i=0;
FILE*stream=fopen(filename, "rt");
if(!stream)
	{
	putch(7);
	return -1; //ERROR condition
	}

for(i=0; i<NUM_REC; i++)
	{
	char *buff;
	fscanf(stream,"%[^\n]",(s+i)->name); fgetc(stream);
	fscanf(stream,"%[^\n]",(s+i)->exam); fgetc(stream);
	for(int j=0; j<SUBJ; j++)
		{
		fscanf(stream,"%[ ]",buff);
		fscanf(stream,"%[^ ]",buff);
		(s+i)->marks[j]=atoi(buff);
		}
	if(feof(stream))
		{
		fclose(stream);
		break;
		}
	while(fgetc(stream)!='\n') ;
	}
//i+=1;
return i;
}

void save(ST *s, char *filename, int limit)
{
char ch;
printf("\n\nCurrent filename is: %s. Change? [yn]",filename);
ch=getche();
if(ch=='y' || ch=='Y')
	{
	printf("Enter New Filename: ");
	scanf("%12s",s);
	}
FILE*save=fopen(filename,"wt");
for(int i=0; i<limit; i++)
	{
	fprintf(save, "%s\n%s\n",(s+i)->name,(s+i)->exam);
	for(int j=0; j<SUBJ; j++)
		{
		fprintf(save,"%d ",(s+i)->marks[j]);
		}
	fprintf(save,"\n");
	}
fclose(save);
}

void addrec(ST *s, int *ip)
{
int it=*ip;
puts("\n\n"); //3 line scroll (puts appends \n)
fflush(stdin);
printf("Enter Student's NAME: ");
gets((s+it)->name);
fflush(stdin);
printf("Enter %s's Exam Number: ",(s+it)->name);
gets((s+it)->exam);
fflush(stdin);
for(int i=0;i<SUBJ;i++)
	{
	printf("Enter Marks for Subject No. %d",i+1);
	scanf("%d",&s[it].marks[i]);
	}
*ip+=1; // auto inc. rec. ctr. " j " in main
}

void edit(ST *s, int l)
{
char ch;
do	{
	printf("Display records first? [yn] : ");
	ch=getche();
	} while(lower(ch)!='y' && lower(ch)!='n') ;
if(lower(ch)=='y')	showrec(s, l);
printf("Enter Rec # to edit: ");
scanf("%d",&l);
addrec(s, &l);
}

char lower(char ch)
{
if(ch>64 && ch<91) ch^=0x20;
return ch;
}

void showhead()
{
clrscr();
gotoxy(59,1);
printf("S U B J E C T S");
gotoxy(1,2);
printf("REC# ");
printf("%-30s","Student's Name");
printf("%-15s","Exam Number");
for(int j=0; j<SUBJ; j++)
	printf("%-5d",j+1);
printf("\bTotal");
gotoxy(1,3);
while(wherex()<79) printf("*");
}

void showrec(ST *s,int limit)
{
for(int i=0;i<limit;i++)
	{
	if(i%20==0)
		{
		if(i!=0) {  getch();  }
		showhead();
		}
	gotoxy(1,i+4);
	printf("%4d ",i);
	printf("%-30s",(s+i)->name);
	printf("%-15s",(s+i)->exam);
	for(int j=0; j<SUBJ;j++)
		{ printf("%-3d  ",(s+i)->marks[j]);  }
	printf("%-5d",total(*(s+i)) );
	}
getch();
}


void find(ST *s, int limit)
{
int ch;
do	{
	puts("\nEnter the type of search desired:");
	puts("N: Search for NAME of student ");
	puts("S: Subject-wise topper");
	puts("O: Overall Topper");
	ch=getche();
	ch=lower(ch);
	} while(ch!='n' && ch!='s' && ch!='o');
if(ch=='n')
	{
	char *buff, *tofind;  fflush(stdin);
	buff=(char*)malloc(NAME);   // char is NOT sys.
	tofind=(char*)malloc(NAME); // dep. IS 1 byte.

	printf("Enter the name to Find: ");
	gets(tofind);
	int sl=strlen(tofind);
	for(int i=0;i<limit;i++)
		{
		strcpy(buff,(s+i)->name);
		buff+=sl;	*buff='\0'; buff-=sl;
		if(!stricmp(buff, tofind))
			{
			show1(*(s+i) , "Person found. Records are..." );
			return;
			}
		}
	puts("Reqd. person NOT FOUND!! ");
	getch();
	return;
	}
else if(ch=='s')
	{
	do	{
		printf("\nEnter the Subject No. (1..5): ");
		ch=getche();
		ch-=0x30;
		} while(ch<0 && ch>5) ;
	ch-=1;
	int max=0;
	int nmax=1;
	for(int i=0;i<limit;i++)
		{
		if( (s+i)->marks[ch]>(s+i)->marks[max] )
			{  max=i; nmax=1;	}
		else if( (s+i)->marks[ch]==max )
			{  nmax+=1;  		}
		else {  continue;		}
		}
	char *temp; temp=(char*)malloc(50); //char is
	if(nmax>1)			// ** ALWAYS ** 1byte
		{
		char *t2; t2=(char*)malloc(5); //5 bytes
		itoa(nmax, t2, 10);
		temp="The first topper of ";
		strcat(temp,t2);
		strcat(temp, " is:");
		}

	else temp="The Subject topper is: ";

	show1( *(s+max), temp);
	return;
	}
else if(ch=='o')
	{
	int max=0, mp=0, nmax=0;
	for(int i=0;i<limit;i++)
		{
		if(total(*(s+i)) > total(*(s+max)) )
			{
			max=total(*(s+i) );
			mp=i;  nmax=0;
			}
		if(total(*(s+i)) == max)
			{ nmax+=1; }
		}
	char *temp; temp=(char*)malloc(50);
	if(nmax>0)
		{
		char t2[5];
		itoa(nmax, t2, 10);
		temp="There are ";
		strcat(temp,t2);
		strcat(temp," Toppers, first of which is:");
		}

	else temp="The overall topper is: ";

	show1( *(s+mp), temp);
	return;
	}
}

void show1(ST st, char *textstring)
{
puts("\n\n");
puts(textstring);
printf("\nName     : %s",st.name);
printf("\nExam No. : %s",st.exam);
puts("\nSubject Marks Are... ");
for(int i=0;i<SUBJ;i++)
	{	printf("\tSubj: %2d    Marks: %3d"
						"\n",i+1, st.marks[i]);
	}
getch();
}

int total(ST st)
{
int t=0;
for(int i=0; i<SUBJ;i++)
	{ t+=st.marks[i]; }
return t;
}