#include<iostream>
#include<queue>
using namespace std;
typedef struct process
{
   int pid,arr_time,burst_time,finishing_time,priority;
   float waiting_time,turn_arnd_time;
}process;

process Process[10],p1[10],temp;
queue<int> queue1;
int accept(int ch);
void turn_wait(int n);
void display(int n);
void ganttrr(int n);
int main()
{
   int i,n,ts,ch,j,x;
   Process[0].turn_arnd_time=0;
   Process[0].waiting_time=0;
   n=accept(ch);
   ganttrr(n);
   turn_wait(n);
   display(n);
   return 0;
}

int accept(int ch) //functions for accepting inputs from the user
{
   int i,n;
   cout<<"\nEnter the no. of process : ";
   cin>>n;
   if(n==0)
   {
      cout<<endl<<"wrong no. of processes entered";
      exit(1);
   }
   cout<<"Provide inputs"<<endl;
   for(i=1;i<=n;i++)
   {
      cout<<endl<<"Arrival time for process P"<<i<<" : ";
      cin>>Process[i].arr_time;
      Process[i].pid=i;
      cout<<endl<<"Burst time for process P"<<i<<" : ";
      cin>>Process[i].burst_time;
      cout<<endl<<endl;
   }
   cout<<endl<<"Table of inputs provided by you : "<<endl<<endl;

   cout<<"==============================================================="<<endl;
   cout<<endl<<"Process\tAT\tBT";
   for(i=1;i<=n;i++)
      {

	  printf("\nP%d\t%d\t%d",Process[i].pid,Process[i].arr_time,Process[i].burst_time);

      }
   printf("\n============================================================");

   for(i=1;i<=n;i++) // creating dummy array
    {
		p1[i]=Process[i];
    }
   return n;
}

void ganttrr(int n)		// Displaying ghant chart
{
   int i,ts,m,nextval,nextarr;
   nextval=Process[1].arr_time;
   cout<<"\nEnter time slice : ";
   cin>>ts;

   nextval=p1[1].arr_time;
   cout<<endl<<"\nGantt chart :\n"<<endl;
   cout<<p1[1].arr_time;

   for(i=1;i<=n,p1[i].arr_time<=nextval;i++)
   queue1.push(p1[i].pid);
   nextarr=p1[i].arr_time;
   while(!queue1.empty())
   {
      m=queue1.front();
      queue1.pop();
      if(p1[m].burst_time>=ts)
         nextval=nextval+ts;
      else
         nextval=nextval+p1[m].burst_time;
      cout<<"->P"<<p1[m].pid<<"->"<<nextval;
      p1[m].burst_time=p1[m].burst_time-ts;
      if(nextval<nextarr)
      {
         if(p1[m].burst_time>0)
         queue1.push(m);
         if(p1[m].burst_time<=0)
         Process[m].finishing_time=nextval;
      }
      else
      {
         while(i<=n&&p1[i].arr_time<=nextval)
         {
            queue1.push(p1[i].pid);
            i++;
         }
      if(i<=n)
         nextarr=p1[i].arr_time;
      if(p1[m].burst_time>0)
         queue1.push(m);
      if(p1[m].burst_time<=0)
         Process[m].finishing_time=nextval;
      }
   }
}

void turn_wait(int n)	//	Calculating turn around time and waiting time
{
   int i;
   for(i=1;i<=n;i++)
   {
      Process[i].turn_arnd_time=Process[i].finishing_time-Process[i].arr_time;
      Process[i].waiting_time=Process[i].turn_arnd_time-Process[i].burst_time;
      Process[0].turn_arnd_time=Process[0].turn_arnd_time+Process[i].turn_arnd_time;
      Process[0].waiting_time=Process[0].waiting_time+Process[i].waiting_time;
   }
   Process[0].turn_arnd_time=Process[0].turn_arnd_time/n;
   Process[0].waiting_time=Process[0].waiting_time/n;
}

void display(int n)    // Display result
{
   int i;
   cout<<"\n\n-------------------RESULT----------------------------------\n";
   cout<<"\nProcess\tAT\tBT\tFT\tTAT\tWT";

   for(i=1;i<=n;i++)
   {
   cout<<"\nP"<<Process[i].pid<<"\t"<<Process[i].arr_time<<"\t"<<Process[i].burst_time<<"\t"<<Process[i].finishing_time<<"\t"<<Process[i].turn_arnd_time<<"\t"<<Process[i].waiting_time;
   }

   cout<<"\n\n-----------------------------------------------------------";

   cout<<"\nAverage Turn Around Time: "<<Process[0].turn_arnd_time;
   cout<<"\nAverage Waiting Time: "<<Process[0].waiting_time<<endl;
}