PrioritySchedulingAlgorithm.java

import java.util.Scanner;

public class priority {

  public static void main(String args[]) {
    Scanner s = new Scanner(System.in);

    int x, n, p[], pp[], bt[], w[], t[], awt, atat, i, ct[];

    p = new int[10];
    pp = new int[10];
    bt = new int[10];
    w = new int[10];
    t = new int[10];
    ct = new int[10];

    // n is number of process
    // p is process
    // pp is process priority
    // bt is process burst time
    // w is wait time
    // t is turnaround time
    // awt is average waiting time
    // atat is average turnaround time

    System.out.print("Enter the number of process : ");
    n = s.nextInt();
    System.out.print("\n\t Enter burst time : time priorities \n");

    for (i = 0; i < n; i++) {
      System.out.print("\nProcess[" + (i + 1) + "]:");
      bt[i] = s.nextInt();
      pp[i] = s.nextInt();
      p[i] = i + 1;
    }

    // sorting on the basis of priority
    for (i = 0; i < n - 1; i++) {
      for (int j = i + 1; j < n; j++) {
        if (pp[i] > pp[j]) {
          x = pp[i];
          pp[i] = pp[j];
          pp[j] = x;
          x = bt[i];
          bt[i] = bt[j];
          bt[j] = x;
          x = p[i];
          p[i] = p[j];
          p[j] = x;
        }
      }
    }
    w[0] = 0;
    awt = 0;
    t[0] = bt[0];
    atat = t[0];
    for (i = 1; i < n; i++) {
      w[i] = t[i - 1];
      awt += w[i];
      t[i] = w[i] + bt[i];
      ct[i] = t[i];
      atat += t[i];
    }

    // Displaying the process

    System.out.print("\n\nProcess \t Burst Time \t Wait Time \t Turn Around Time   Priority \n");
    for (i = 0; i < n; i++)
      System.out.print(
          "\n   " + p[i] + "\t\t   " + bt[i] + "\t\t     " + w[i] + "\t\t     " + t[i] + "\t\t     " + pp[i] + "\n");
    awt /= n;
    atat /= n;
    System.out.print("\n Average Wait Time : " + awt);
    System.out.print("\n Average Turn Around Time : " + atat);

  }
}