The Snake Game in C++

It is similar to the game which was very common in mobiles few years back. The snake eats food items to increase its length and tries to avoid obstacles in order to win the game. The game has 3 modes- easy, normal and hard. Hard mode has the maximum number of obstacles. The obstacles and food items are generated at random so every time the game is different from the last time. 

The source code is given below-

#include<iostream.h>
#include<conio.h>
#include<process.h>
#include<time.h>
#include<stdlib.h>
//created by Aditya Vijayvergia 
//uploaded at thecodingedge.blogspot.com
int snake[40][2],point[20][2],dead[200][2],nd,len,n=20,m=39,pos[2];
void create()
{
   int i;
   len=5;
   srand(time(NULL));
   for(i=0;i<len;i++)
       {
  snake[i][1]=i;
       }
   for(i=0;i<20;i++)
      {
  point[i][0]=rand() %20;
  point[i][1]=rand() %40;
      }
   srand(time(NULL));
   for(i=0;i<nd;i++)
      {
  dead[i][0]=rand() %20;
  dead[i][1]=rand() %40;
      }
}

int found(int x,int y)
{
for(int i=0;i<len;i++)
   if(snake[len-1][0]==x&&snake[len-1][1]==y)
     return 2;

   else if(snake[i][0]==x&&snake[i][1]==y)
     return 1;
return 0;
}

int ifdead(int x,int y)
{

   for(int j=0;j<nd;j++)
   if(dead[j][0]==x&&dead[j][1]==y)
       return 1;
   return 0;
}
int ifpoint(int x,int y)
{
   for(int i=0;i<20;i++)
   {
   if(point[i][0]==x&&point[i][1]==y)
      return 1;
   }
   return 0;
}

void show()
{
   //cout<<"show running";
   clrscr();
   cout<<"\n";
   for(int k=0;k<m+1;k++)
   cout<<"__";
   cout<<"\n";
   for(int i=0;i<n;i++)
   {
   cout<<"|";
   for(int j=0;j<m;j++)
   {
       if(found(i,j)==2)
       cout<<" m";
       else if(found(i,j)==1)
       cout<<" o";
       else if(ifpoint(i,j))
       cout<<" *";
       else
       if(ifdead(i,j))
       cout<<" X";
       else
       cout<<"  ";
   }
   cout<<"|";
   }
   for(k=0;k<m+1;k++)
   cout<<"__";
}

void changepoint(int x,int y)
{
   for(int i=0;i<20;i++)
   if(point[i][0]==x&&point[i][1]==y)
   {
       point[i][0]=-1;
       point[i][1]=-1;
   }
}


void move(int x,int y)
{
    x=(x+n)%n;
    y=(y+m)%m;
    if(ifpoint(x,y))
    {
  pos[0]=x;
  pos[1]=y;
  changepoint(x,y);

    }
    else
    if(ifdead(x,y))
    {
      clrscr();
      cout<<"\n\n\n\t\tGAME OVER\n\n\t\tScore:"<<len-5;

      getch();
      exit(0);
    }
    for(int i=0;i<len-1;i++)
    for(int j=0;j<2;j++)
       snake[i][j]=snake[i+1][j];
    snake[i][0]=x;
    snake[i][1]=y;
    //}
    show();

    if(snake[len-1][0]==pos[0]&&snake[len-1][1]==pos[1])
    {
 len++;
  if(len-5==20)
  {
     clrscr();
     cout<<"\n\n\n\t\tVICTORY";
     exit(0);
  }
 for(i=len-1;i>0;i--)
 for(j=0;j<2;j++)
     snake[i][j]=snake[i-1][j];
 snake[0][0]=pos[0];
 snake[0][1]=pos[1];
 pos[0]=-1;
 pos[1]=-1;
    }
}

void menu()
{
   int choice;
   cout<<"\n\n\tSANKE GAME";
   cout<<"\n\n\n1.easy\n2.normal\n3.hard";
   cin>>choice;
   switch(choice)
   {

   case 1:nd=50;
   break;
   case 2:nd=125;
   break;
   case 3:nd=200;
   break;
   }
}

void main()
{
    clrscr();
    menu();
    create();
    show();
    pos[0]=-1;
    pos[1]=-1;
    char m;
    while(1)
    {
    cout<<"\n\t\t";
    cout<<"enter choice:";
    cin>>m;
    switch(m)
    {
    case 'd':move(snake[len-1][0],snake[len-1][1]+1);
      break;
    case 'w':move(snake[len-1][0]-1,snake[len-1][1]);
      break;
    case 's':move(snake[len-1][0]+1,snake[len-1][1]);
      break;
    case 'a':move(snake[len-1][0],snake[len-1][1]-1);
      break;
    case 'p':exit(0);
    }
    }
}

Sample output is given below.