Dining Philosopher's Algorithm...

/*********************************************************************************
By  => Ajit Medhekar... Xtream Kings...  K.K.Wagh COE,Nashik...
            Ajit's Blog :- http://ammedhekar.blogspot.com
*********************************************************************************/
#include<stdio.h>
#include<conio.h>
#include<iostream.h>
#include<stdlib.h>
//status:1=eating,status:0:thinking
class semaphore
{
   public:
   int s;
   semaphore()
   {
      s=1;
   }
   int wait()
   {
      int s1;
      s1=s;
      s1--;

      if(s1<0)
      {
cout<<"\nblock";
return(1);
      }
      else
      {
s--;
cout<<"\nWait:"<<s;
return(0);
      }
   }
   void signal()
   {  int s1;
      s1=s;
      s1++;

      if(s1<=0)
      {
cout<<"\nblocked philosophers can eat now";
      }
      else
      {
s++;
cout<<"\nsignal:"<<s;
      }
   }
};


void main()
{
   int ch,phil,status[10],i,block1,block2;
   semaphore chopstik[5];
   clrscr();
   for(i=1;i<=5;i++)
   {
      status[i]=0;        //thinking
   }
   do
   {
      cout<<"\n1.eat\n2.think\n3.status\n4.Allowed philosophers for eating\n5.exit";
      cout<<"\nEnter choice:";
      cin>>ch;
      switch(ch)
      {
case 1:
cout<<"\nEnter the philosopher who wants to eat:";
cin>>phil;
if(status[phil]==1)
cout<<"\nAlready eating ;)";
else
{
block1=chopstik[phil].wait();
block2=chopstik[(phil+1)%5].wait();
status[phil]=1;
if(block1==1 || block2==1)
{
  if(block1==0)
  {
     chopstik[phil].signal();
  }
  else if(block2==0)
  {
     chopstik[(phil+1)%5].signal();
  }
  status[phil]=0;

}
}
break;
case 2:
cout<<"\nEnter the philosopher who wants to think:";
cin>>phil;
if(status[phil]==0)
cout<<"\nAlready thinking ;)";
else
{
chopstik[phil].signal();
chopstik[(phil+1)%5].signal();
status[phil]=0;
}
break;
case 3:
for(i=0;i<5;i++)
{
  cout<<"\nPhilosopher "<<i+1<<":";
  if(status[i+1]==1)
  {
    cout<<"eating";
  }
  else
  {
     cout<<"thinking";
  }
}
break;
case 4:
      for(i=1;i<=5;i++)
      {
 if(chopstik[i].s==1 && chopstik[((i+1)%5)].s==1)
 {
    cout<<"\nPhilosopher "<<i<<" is allowd to eat";
 }
      }
      break;
case 5:
exit(0);
      }
   }while(ch<=5);
   getch();
}