Sudoku

Code:

/*********************************\
The Program for Cross sum sudoku.
Date: 20-10-2011
Devloped by:Balvant C Jat
Contact:-+919537718497
\*********************************/
#include<stdio.h>
#include<conio.h>
#include<dos.h>
void main()
{
	int a,b,c,d,i,j,f,g,x,y,t;         /*all variable declaration*/
top:
	clrscr();
	f=2,g=12;
	x=20,y=16;
	_setcursortype(_NORMALCURSOR);
	printf("\n Enter the SUM which is devided by 3:");
	scanf("%d",&b);                          /* Number scaned for cross sum*/
	if(b%3==0)          /* Checks that given no is devided by column*/
	{
		c=(9-1)/2;        /*Total box-1 divided by 2 and store result in c*/
		d=b/3;            /* given no devided by column and store reslut in d*/
		i=d-c;           /* create starting point by d-c */
		t=d;            /* t for position */
		for(j=0;t>0;j++)      /* This for loop for length of output digit */
		{
			t/=10;
		}
		/* This if ladden is define position of output 
		digit*/
		if(j==3)
			x=19;
		else if(j==5)
			x=18;
		t=8;
		clrscr();
		gotoxy(x+t,y);
		printf("%d",i++);
		gotoxy(x+2*t,y+2*t);
		printf("%d",i++);
		gotoxy(x,y+t);
		printf("%d",i++);
		gotoxy(x,y+2*t);
		printf("%d",i++);
		gotoxy(x+t,y+t);
		printf("%d",i++);
		gotoxy(x+2*t,y);
		printf("%d",i++);
		gotoxy(x+2*t,y+t);
		printf("%d",i++);
		gotoxy(x,y);
		printf("%d",i++);
		gotoxy(x+t,y+2*t);
		printf("%d",i++);
		_setcursortype(_NOCURSOR);
		sleep(1);
		/* The below for loop is used for draw boxes */
		for(i=0;i<4;i++)
		{
			gotoxy(17,g);
			for(j=1;j<25;j++)
			{
				printf("%c",f);
			}
			g+=8;
			sleep(1);
		}
		g=16;
		for(i=0;i<4;i++)
		{
			c=12;
			gotoxy(g,c);
			for(j=1;j<26;j++,c++)
			{
				gotoxy(g,c);
				printf("%c",f);
			}
			g+=8;
			sleep(1);
		}
	}
	else
		printf("\n Entered sum must be devided by 3.");
	getch();
	gotoxy(16,45);
	printf("Press ");
	textcolor(RED+BLINK);
	cprintf("ESC ");
	printf("to exit. Otherwise press any key...");
	if(getch()!=27)
		goto top;
	else
		exit(0);
}