TYBcs OS-Syspro Slip 10-2 | IProgramX

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

typedef struct process_info
{
char pname[20];
int at,bt,ct,bt1;
struct process_info *next;
}NODE;

int n;
NODE *first,*last;

void accept_info()
{
NODE *p;
int i;

printf("Enter no.of process:");
scanf("%d",&n);

for(i=0;i<n;i++)
{
p = (NODE*)malloc(sizeof(NODE));

printf("Enter process name:");
scanf("%s",p->pname);

printf("Enter arrival time:");
scanf("%d",&p->at);

printf("Enter first CPU burst time:");
scanf("%d",&p->bt);

p->bt1 = p->bt;

p->next = NULL;

if(first==NULL)
first=p;
else
last->next=p;

last = p;
}
}

void print_output()
{
NODE *p;
float avg_tat=0,avg_wt=0;

printf("pname\tat\tbt\tct\ttat\twt\n");

p = first;
while(p!=NULL)
{
int tat = p->ct-p->at;
int wt = tat-p->bt;

avg_tat+=tat;
avg_wt+=wt;

printf("%s\t%d\t%d\t%d\t%d\t%d\n",
p->pname,p->at,p->bt,p->ct,tat,wt);

p=p->next;
}

printf("Avg TAT=%f\tAvg WT=%f\n",
avg_tat/n,avg_wt/n);
}

void print_input()
{
NODE *p;

p = first;

printf("pname\tat\tbt\n");
while(p!=NULL)
{
printf("%s\t%d\t%d\n",
p->pname,p->at,p->bt1);
p = p->next;
}
}

void sort()
{
NODE *p,*q;
int t;
char name[20];

p = first;
while(p->next!=NULL)
{
q=p->next;
while(q!=NULL)
{
if(p->at > q->at)
{
strcpy(name,p->pname);
strcpy(p->pname,q->pname);
strcpy(q->pname,name);

t = p->at;
p->at = q->at;
q->at = t;

t = p->bt;
p->bt = q->bt;
q->bt = t;

t = p->ct;
p->ct = q->ct;
q->ct = t;

t = p->bt1;
p->bt1 = q->bt1;
q->bt1 = t;
}

q=q->next;
}

p=p->next;
}
}

int time;

NODE * get_sjf()
{
NODE *p,*min_p=NULL;
int min=9999;

p = first;
while(p!=NULL)
{
if(p->at<=time && p->bt1!=0 &&
p->bt1<min)
{
min = p->bt1;
min_p = p;
}
p=p->next;
}

return min_p;
}

struct gantt_chart
{
int start;
char pname[30];
int end;
}s[100],s1[100];

int k;

void sjfp()
{
int prev=0,n1=0;
NODE *p;

while(n1!=n)
{
p = get_sjf();

if(p==NULL)
{
time++;
s[k].start = prev;
strcpy(s[k].pname,"*");
s[k].end = time;

prev = time;
k++;
}
else
{
time++;
s[k].start = prev;
strcpy(s[k].pname, p->pname);
s[k].end = time;

prev = time;
k++;

p->ct = time;
p->bt1--;

if(p->bt1==0)
n1++;
}

print_input();
sort();
}
}

void print_gantt_chart()
{
int i,j,m;

s1[0] = s[0];

for(i=1,j=0;i<k;i++)
{
if(strcmp(s[i].pname,s1[j].pname)==0)
s1[j].end = s[i].end;
else
s1[++j] = s[i];
}

printf("%d",s1[0].start);
for(i=0;i<=j;i++)
{
m = (s1[i].end - s1[i].start);

for(k=0;k<m/2;k++)
printf("-");

printf("%s",s1[i].pname);

for(k=0;k<(m+1)/2;k++)
printf("-");

printf("%d",s1[i].end);
}
}

int main()
{
accept_info();
sort();
sjfp();
print_output();
print_gantt_chart();

return 0;
}