fcfs

#include<stdio.h>
#include<stdlib.h>

struct Process
{
int first_bt;
int next_bt;
int at;
int ft;
int tat;
int wt;
int temp_bt;
}P[100];

struct Schedule
{
int pid;
int endtime;
}sch[100];
// sch[1].pid=3
// sch[1].endtime=13
int sch_cnt ;
int ct;
int np;
int i;

void take_input()
{
printf("Enter the number of processes:");
scanf("%d",&np);
for(i=0;i<np;i++)
{
printf("Enter the arrival time:");
scanf("%d",&P[i].at);

printf("Enter the first burst time:");
scanf("%d",&P[i].first_bt);
P[i].temp_bt=P[i].first_bt;
}
}

void take_rinput()
{
for(i=0;i<np;i++)
{
P[i].next_bt=rand()%10+1;
P[i].temp_bt=P[i].first_bt;
}
}
int getProcessByFCFS()
{
int minp=-1;
int minat=10000;

for(i=0;i<np;i++)
{
if(P[i].at<=ct && P[i].temp_bt>0 && P[i].at<minat)
{
minp=i;
minat=P[i].at;
}
}
return minp;
}

void showGanttChart()
{
for(i=0;i<sch_cnt*5;i++)
printf("-");
printf("\n|");

for(i=0;i<sch_cnt;i++)
printf(" P%d |",sch[i].pid);
printf("\n");

for(i=0;i<sch_cnt*5;i++)
printf("-");
printf("\n0");

for(i=0;i<sch_cnt;i++)
printf("%5d",sch[i].endtime);
}

void print_output()
{
float avgtat=0,avgwt=0;
printf("\n");
printf("\nPID\tFBT\tNBT\tAT\tFT\tTAT\tWT\n");
for(i=0;i<np;i++)
{
printf("\nP%d\t%d\t%d\t%d\t%d\t%d\t%d\n",i,P[i].first_bt,P[i].next_bt,P[i].at,P[i].ft,P[i].tat,P[i].wt);
avgtat = avgtat+P[i].tat;
avgwt = avgwt+P[i].wt;
}

avgtat=avgtat/np;
avgwt=avgwt/np;

printf("Average turn around time:%f",avgtat);
printf("\nAverage waiting time:%f\n",avgwt);
}

void main()
{
take_input();
while(1)
{
int x=getProcessByFCFS(); // x=4
if(x==-1)
break;

sch[sch_cnt].pid=x;
ct+=P[x].temp_bt; //ct=6
P[x].temp_bt=0;
P[x].ft=ct;
sch[sch_cnt].endtime=ct;
sch_cnt++;
P[x].tat=P[x].ft-P[x].at;
P[x].wt=P[x].tat-P[x].first_bt;
}

showGanttChart();
print_output();

take_rinput();

while(1)
{
int x=getProcessByFCFS();
if(x==-1)
break;
sch[sch_cnt].pid=x;
ct+=P[x].temp_bt;
P[x].temp_bt=0;
P[x].ft=ct;
sch[sch_cnt].endtime=ct;
sch_cnt++;
P[x].tat=P[x].ft-P[x].at;
P[x].wt=P[x].tat-P[x].first_bt-P[x].next_bt-2;
}
showGanttChart();
print_output();

}