SJF Algorithm in C not working properly - c

Question

#include<stdio.h>
typedef struct nonpresjf
{
int at,bt,ft,tat,wt,id;
}nonpresjf;
nonpresjf p[20],p1[20],aux;
int main()
{
int i,limit,nextval,m,min,j;
float mediaperm=0,mediaespera=0;
p[0].wt=p[0].tat=0;
int n=3;
p[0].at=3;
p[1].at=5;
p[2].at=7;
p[0].bt=9;
p[1].bt=3;
p[2].bt=2;
limit=p[0].at;
for (i=0;i<n;i++){
for(j=i+1;j<n;j++){
if(p[i].at<p[j].at){
aux=p[j];
p[j]=p[i];
p[i]=aux;
}
}
}
for(i=0;i<n;i++)
limit+=p[i].bt;
for(i=0;i<n;i++)
p1[i]=p[i];
printf("\n\n Diagram: ");
printf("%d",p[0].at);
nextval=p[0].at;
m=0;
do
{
min = 9999;
for(i=0;p[i].at<=nextval && i<n ;i++)
if(p[i].bt<min && p[i].bt>0)
{
m=i;
min=p[i].bt;
}
nextval+=p[m].bt;
p[m].bt=0;
printf("->P%d->%d",m,nextval);
if(p[m].bt==0)
{
p[m].ft=nextval;
p[m].tat=p[m].ft-p[m].at;
p[m].wt=p[m].tat-p1[m].bt;
p[0].tat+=p[m].tat;
p[0].wt+=p[m].wt;
}
}while(nextval<limit);
p[0].tat=p[0].tat/n;
p[0].wt=p[0].wt/n;
printf("\n\n-----------TABLE-------------------\n");
printf("\nProcess\tArrival\tBurst\tTurnAround\tWaitTime\n");
for(i=0;i<n;i++)
printf("\nP%d\t%d\t%d\t\t%d\t\t%d\n",p[i].id,p[i].at,p1[i].bt,p[i].tat,p[i].wt);
printf("\n\n--------------------------------\n");
}
return 0;
}
Due to the fact that this is an important assignment and that my other post wasn't answered this is another attemp at programing this.
It seems to be working if arrival times are in order but it goes on an infinite loop randomly with burst times. I debugged it an has something to do with nextval<limit nextval never hits limit this happens sometimes.
I think the sort by aT doesn't work properly too, I was suggested in my other post to sort it starting in j=i+1 but that way the theoretically correct output is wrong.
Input:
number of process: 3
Arrival Time0: 3
Arrival Time1: 5
Arrival Time2: 7
Burst time 0: 9
Burst time 1: 3
Burst time 2: 2
Expected output.
-----------TABLE-------------------
Process Arrival Burst TurnAround WaitTime
P0 3 9 9 0
P1 5 3 12 9
P2 7 2 7 5
Actual output.
-----------TABLE-------------------
Process Arrival Burst TurnAround WaitTime
P0 3 9 9 4
P1 5 3 7 9
P2 7 2 12 5
If input was:
number of process: 3
Arrival Time0: 5
Arrival Time1: 2
Arrival Time2: 7
Burst time 0: 3
Burst time 1: 9
Burst time 2: 2
I'd get an infinite loop