Priority

#include<stdio.h>
struct data{
int p_no,bt_tm,pri,tat,wt;
}a[20],temp;
void main()
{
int n,i,tta=0,twt=0,ttat=0,j;
double atat,awt;
printf("Enter the no. of process : ");
scanf("%d",&n);
for(i=0;i<n;i++)
{
printf("Enter the process no., Burst time and Priority : ");
scanf("%d %d %d",&a[i].p_no,&a[i].bt_tm,&a[i].pri);
}
for(i=0;i<n;i++){
for(j=i+1;j<n;j++){
if(a[i].pri<a[j].pri){
temp=a[i];
a[i]=a[j];
a[j]=temp;
}}}
for(i=0;i<n;i++){
a[i].tat=tta+a[i].bt_tm;
tta=tta+a[i].bt_tm;
}
for(i=0;i<n;i++){
a[i].wt=a[i].tat-a[i].bt_tm;
}
for(i=0;i<n;i++){
ttat=ttat+a[i].tat;
twt=twt+a[i].wt;
}
atat=ttat/n;
awt=twt/n;
printf("\nProcess id\tBrust time\tPriority\tTA_T\t\tW_T\n");
for(i=0;i<n;i++)
{
printf("P%d\t\t%d\t\t%d\t\t%d\t\t%d\n",a[i].p_no,a[i].bt_tm,a[i].pri,a[i].tat,a[i].wt);
}
printf("Average trun around time = %lf\n",atat);
printf("Average waiting time = %lf\n",awt);
printf("GANTT CHART\n");
printf("0");
for(i=0;i<n;i++){
printf("\tP%d\t%d",a[i].p_no,a[i].tat);
}
printf("\n");
}