#include<stdio.h>
#include<string.h>
#include<stdlib.h>
struct process
{
  char name[20];
  int at,tt,bt,wt,ct,status;
}p[20],temp;

struct done
{
  char name[20];
  int st,ct;
}d[20];

int n,num,idle=0;
float average_wt=0,average_tt=0;

void read(){
	printf("ENTER THE NUMBER OF PROCESSES : ");
	scanf("%d",&n);
	for(int i=0;i<n;i++)            
	{
	printf("\nENTER DETAILS OF PROCESS %d",i+1);
	printf("\nPROCESS NAME : ");
	scanf(" %s",p[i].name);
	printf("ARRIVAL TIME : ");
	scanf("%d",&p[i].at);
	printf("BURST TIME : ");
	scanf("%d",&p[i].bt);
	p[i].status = 0;
  }
}

void sort(){
	for(int i=0;i<n;i++) 
	{
	for(int j=0;j<n-i-1;j++)
	{
	  if(p[j].at > p[j+1].at)
	  {
		temp = p[j];
		p[j] = p[j+1];
		p[j+1] = temp;
	  }
	}
	}
}

void FCFS(){
	int i,j;
	for(i=0,j=0,num=0;j<n;)
	{
	if(p[j].at<=i && p[j].status==0)
	{
	  if(idle==1)
	  {
		d[num].ct=i;
		num++;
		idle = 0;
	  }
	  strcpy(d[num].name,p[j].name);
	  d[num].st = i;
	  d[num].ct = i + p[j].bt;
	  p[j].wt = d[num].st - p[j].at;
	  p[j].tt = p[j].wt + p[j].bt;
	  p[j].ct = d[num].ct;
	  i = d[num].ct;
	  p[j].status = 1;
	  j++;
	  num++;

	}
	else if(idle == 0)
	{
	  strcpy(d[num].name,"Idle");
	  d[num].st = i;
	  i++;
	  idle = 1;
	}
	else
	{
	  i++;
	}
	}
}

void NP-SJF(){
	int i,j,ls,fnd,min;
	for(i=0,ls=0,num=0,idle=0;ls<n;){
		for(j=0,fnd=0;j<n;j++)
		{
			if(i>=p[j].at && p[j].status==0)
			{
				if(fnd==0){
				  min = j;
				  fnd = 1;
				}
				else if(fnd!=0 && p[min].bt>p[j].bt){
				  min = j;
				}
			}
		}
		if(idle==0 && fnd==0){
			strcpy(d[num].name,"Idle");
			d[num].st = i;
			i++;
			idle = 1;
		}
		else if(fnd==1){
			if(idle==1){
				d[num].ct = i;
				num++;
				idle = 0;
			}
			strcpy(d[num].name,p[min].name);
			p[min].status =1;
			d[num].st = i;
			d[num].ct = i + p[min].bt;
			i = d[num].ct;
			p[min].ct = d[num].ct;
			p[min].tt = p[min].ct - p[min].at;
			p[min].wt = p[min].tt - p[min].bt;
			num++;
			ls++;
		}
		else{
			i++;
		}
	}
}

void print(){
	printf("\nPROCESS NAME\t  ARRIVAL TIME\t  BURST TIME\tCOMPLETION TIME\t\tWAITING TIME\t\tTURNAROUND TIME\n");
	for(int i=0;i<n;i++)
	{
	printf("    %s\t\t\t%d\t\t%d\t\t%d\t\t\t%d\t\t\t\%d\n",p[i].name,p[i].at,p[i].bt,p[i].ct,p[i].wt,p[i].tt);
	average_wt+=p[i].wt;
	average_tt+=p[i].tt;
	}
	printf("\n\nGANTT CHART ");
	printf("\n----------------------------------------------------------\n");
	for(int i=0;i<num;i++)
	{
	  printf("|");
	  printf("   %s\t",d[i].name);
	}
	printf(" |");
	printf("\n----------------------------------------------------------\n");
	for(int i=0;i<num;i++)
	{
	  printf("%d\t",d[i].st);
	}
	printf("%d\t",d[num-1].ct);
	printf("\n\nAVERAGE WAITING TIME : %f",(average_wt/n));
	printf("\nAVERAGE TURNAROUND TIME : %f\n",(average_tt/n));
}
void main()
{
	int arg1,arg2;
	
	while(1){
		printf("Enter your choice:\n");
		printf("1. Non-Preemptive\n2. Preemptive\n0.Exit\n");
		scanf("%d",&arg1);
		switch(arg1){
			case 1:
			{
				printf("Enter your choice:\n");
				printf("1. FCFS\n2. SJF\n3. Priority");
				scanf("%d",&arg2);
				switch(arg2){
					case 1://FCFS
					{
						read();
						sort();
						FCFS();
						print();
						break;
					}
					case 2://SJF
					{
						read();
						NP-SJF();
						print();
						break;
					}
				}
				break;
			}
			case 0:
				exit(0);
		}
	}
	

}