Implement the FCFS(First come first serve) for, Given the list of processes, their CPU burst times and arrival times, print the Gantt chart for FCFS and also compute and print the average waiting time and average turnaround time.

#include<string.h>
#include<stdio.h>
#include<string.h>

 void main()

{

float avgwt,avgtt;
char pname[10][10],c[10][10];
int wt[10],tt[10],bt[10],at[10],t,q,i,n,sum=0,sbt=0,ttime,j,ss=0;

printf("\n\n Enter the number of processes: ");
scanf("%d",&n);

printf("\n\n Enter the NAME , BURST TIME and ARRIVAL TIME of the process");

for(i=0;i<n;i++)

     {

         printf("\n\n NAME : "); scanf("%s",&pname[i]);
printf("\n BURST TIME : "); scanf("%d",&bt[i]);

printf("\n ARRIVAL TIME : "); scanf("%d",&at[i]);

     }

for(i=0;i<n;i++)

for(j=i+1;j<n;j++)

  {

      if(at[i]>at[j])

{

 t=at[i];

 at[i]=at[j];

 at[j]=t;

 q=bt[i];

 bt[i]=bt[j];

 bt[j]=q;

 strcpy(c[i],pname[i]);

 strcpy(pname[i],pname[j]);

 strcpy(pname[j],c[i]);

}

     }

  wt[0]=0;

 for(i=0;i<n;i++)
 {
    wt[i+1]=wt[i]+bt[i];
    sum=sum+(wt[i]-at[i]);
    sbt=sbt+(wt[i+1]-at[i]);
    ss=ss+bt[i];
}

avgwt=(float) sum/n;
avgtt=(float)sbt/n;
printf("\n\n Average waiting time = %f",avgwt);
printf("\n\n Average turn-around time = %f",avgtt);
printf("\n\n GANTT CHART\n");

for(i=0;i<n;i++)
printf("|\t%s\t",pname[i]);
printf("|");

printf("\n");

for(i=0;i<n;i++)

printf("%d\t\t",wt[i]);

printf("%d\n",ss);

printf("\n");

}


OUTPUT-->

Enter the number of processes: 4

Enter the NAME , BURST TIME and ARRIVAL TIME of the process NAME : p1

BURST TIME : 4 ARRIVAL TIME : 0

NAME : p2

BURST TIME : 9

ARRIVAL TIME : 2

NAME : p3

BURST TIME : 8

ARRIVAL TIME : 4

NAME : p4

BURST TIME : 3

ARRIVAL TIME : 3

Average waiting time = 6.000000

Average turn-around time = 12.000000

GANTT CHART

|   p1 | p2   | p4  | p3
0 4 13 16 24