c program to implement non preemptive priority scheduling algorithm
#include<stdio.h> int main() { int bt[20],p[20],wt[20],tat[20],pr[20],i,j,n,total=0,pos,temp,avg_wt,avg_tat; printf("Enter Total Number of Process:"); scanf("%d",&n); printf("\nEnter Burst Time and Priority\n"); for(i=0;i<n;i++) { printf("\nP[%d]\n",i+1); printf("Burst Time:"); scanf("%d",&bt[i]); printf("Priority:"); scanf("%d",&pr[i]); p[i]=i+1; //contains process number } //sorting burst time, priority and process number in ascending order using selection sort for(i=0;i<n;i++) { pos=i; for(j=i+1;j<n;j++) { if(pr[j]<pr[pos]) pos=j; } temp=pr[i]; pr[i]=pr[pos]; pr[pos]=temp; temp=bt[i]; bt[i]=bt[pos]; bt[pos]=temp; temp=p[i]; p[i]=p[pos]; p[pos]=temp; } wt[0]=0; //waiting time for first process is zero //calculate waiting time for(i=1;i<n;i++) { wt[i]=0; for(j=0;j<i;j++) wt[i]+=bt[j]; total+=wt[i]; } avg_wt=total/n; //average waiting time total=0; printf("\nProcess\t Burst Time \tWaiting Time\tTurnaround Time"); for(i=0;i<n;i++) { tat[i]=bt[i]+wt[i]; //calculate turnaround time total+=tat[i]; printf("\nP[%d]\t\t %d\t\t %d\t\t\t%d",p[i],bt[i],wt[i],tat[i]); } avg_tat=total/n; //average turnaround time printf("\n\nAverage Waiting Time=%d",avg_wt); printf("\nAverage Turnaround Time=%d\n",avg_tat); return 0; }
