/*
Author : Narendrakumar Padmani
Email  : n.padmani@yahoo.co.uk
*/
#include<stdio.h>
#include<conio.h>
#include<stdlib.h>
#include<time.h>
#include<dos.h>
#include<graphics.h>
#include<math.h>
char ch[]={' ','@','#'};
char ws[40][40];
int gra[]={0,3,10};
//-----------------------------------
struct snk
	{
	int size,dir;
	struct snk * next;
	};
//-----------------------------------
typedef struct snk turn;
turn * first=NULL,*last=NULL;
int wsx=25,wsy=10,wsdir=3,size=5,bsx=25,bsy=5,bsdir=3,maxl=5,khorak=0,speed=400,level=0,life=5;
//-----------------------------------
char gettextxy(int x,int y)
	{
	return ws[x-1][y-1];
	}
void speed_control(void)
	{
	if (speed<=50)
		return;
	if(speed>=300)
		speed-=20;
	else if(speed>=200)
		speed-=10;
	else if(speed>=100)
		speed-=5;
	return;
	}
void level_check(void)
	{
	static int tot=1;
	tot++;
	if(tot%10==0)
		{
		float a;
		level++;
		for(a=0;a<4*M_PI;a+=0.01f)
			{
			sound(1000*fabs(sin(a)));
			delay(1);
			}
		for(a=0;a<M_PI;a+=.01f)
			{
			sound(1000*fabs(sin(a)));
			delay(10);
			}
		nosound();
		}
	}
//-----------------------------------
void add_node(int s,int d)
	{
	turn * temp;
	temp=(turn *)calloc(sizeof(turn),1);
	temp->size=s;
	temp->dir=d;
	if(first==NULL)
		first=temp;
	else
		last->next=temp;
	last=temp;
	}
//----------------------------------
void discard(void)
	{
	turn * temp;
	if(first==NULL)
		return;
	temp=first;
	first=first->next;
	free(temp);
	return;
	}
//---------------------------------
void putsnack(int x,int y,int ind)
	{
	ws[x-1][y-1]=ch[ind];
	setfillstyle(9,gra[ind]);
	bar(10*(x-1)+10,10*(y-1)+10,10*x+10,10*y+10);
	setcolor(RED);
	rectangle(10*(x-1)+15,10*(y-1)+15,10*x+5,10*y+5);
	return ;
	}
//---------------------------------
void calc_vert(int *x,int *y,int d)
	{
	if(d==1)
		(*y)--;
	else if(d==2)
		(*x)++;
	else if(d==3)
		(*y)++;
	else
		(*x)--;
	if(*x>40)
			*x=1;
		if(*y>40)
			*y=1;
		if(*x<1)
			*x=40;
		if(*y<1)
			*y=40;
	return;
	}
//---------------------------------
void draw_black(void)
	{
	if(first!=NULL)
		(first->size)--;
	calc_vert(&bsx,&bsy,bsdir);
	putsnack(bsx,bsy,0);
	if(first->size==0 && first!=NULL)
		{
		bsdir=first->dir;
		discard();
		}
	return;
	}
//--------------------------------
int draw_white(void)
	{
	char cha;
	calc_vert(&wsx,&wsy,wsdir);
	if( (cha=gettextxy(wsx,wsy))==ch[1] || /*(wsx>40 || wsx<=0 || wsy>40 || wsy<=0*/0)
		return -1;
	if(cha==ch[2])
		{
		maxl++;
		size++;
		khorak=0;
		speed_control();
		level_check();
		putsnack(wsx,wsy,1);
		calc_vert(&wsx,&wsy,wsdir);
		}
	putsnack(wsx,wsy,1);
	return 0;
	}
//----------------------------
int drawsnack()
	{
	if(size<maxl)
		size++;
	if(draw_white()==-1)
		return -1;
	draw_black();
	delay(speed);
	return 0;
	}
//-------------------------
void food(void)
	{
	static int timeout;
	static int x,y;
	if(khorak==0)
		{
		randomize();
		x=rand()%38+1;
		y=rand()%38+1;
		if(gettextxy(x,y)==ch[1])
			return;
		putsnack(x,y,2);
		khorak=1;
		timeout=105;
		}
	else
		{
		timeout--;
		if(timeout==0)
			{
			putsnack(x,y,0);
			khorak=0;
			}
		}
	}

//---------------------------
void snack(void)
	{
	char ch;
	int i;
	static int k=0;
	while(1)
		{
		while(!kbhit() && (i=drawsnack())!=-1 )
			food();
		if(i==-1)
			return;
		ch=getch();
		if(ch=='x')
			return;
		else
			{
			if(ch=='s')
				wsdir++;
			else
				wsdir--;
			if(wsdir<1)
				wsdir=4;
			else if(wsdir>4)
				wsdir=1;
			add_node(size,wsdir);
			size=0;
			if(drawsnack()==-1)
				return ;
			}
		}
	}
//------------------------------
int main(void)
	{
	int i,j,k=0;
	int gdriver = DETECT, gmode, errorcode;
	initgraph(&gdriver, &gmode, "c:\\turboc3");
	for(i=0;i<40;i++)
		for(j=0;j<40;j++)
			ws[i][j]=' ';
	while(life>0)
		{
		wsx=25,wsy=10,wsdir=3,size=5,bsx=25,bsy=5,bsdir=3,maxl=5,khorak=0;
		cleardevice();
		rectangle(2,2,425,425);
		setcolor(RED);
		for(i=1;i<=40;i++)
			for(j=1;j<=40;j++)
				rectangle(10*(i-1)+15,10*(j-1)+15,10*i+5,10*j+5);
		snack();
		while(first!=NULL)
			discard();
		for(i=0;i<40;i++)
			for(j=0;j<40;j++)
				ws[i][j]=' ';
		life--;
		}


	closegraph();
	printf("%d",k);

	return 0;
	}