slip21_2.c

#include <stdio.h>
 #include <stdlib.h>
 #include <time.h>
 #define MAX_PROCESSES 10
 typedef struct {
    int arrival_time;
    int burst_time;
    int priority;
    int waiting_time;
    int turnaround_time;
 } Process;
 void generate_next_burst(Process *p) {
    p->burst_time = rand() % 10 + 1; 
}
 void preemptive_priority_scheduling(Process p[], int n) {
    int current_time = 0;
    int i, j;
    Process temp;
 for (i = 0; i < n; i++) {
 for (j = i + 1; j < n; j++) {
 if (p[i].arrival_time > p[j].arrival_time || (p[i].arrival_time == p[j].arrival_time && p[i].priority < p[j].priority)) {
     temp = p[i];
     p[i] = p[j];
     p[j] = temp;
   }
  }
 }
 
    printf("Gantt Chart:\n");
    for (i = 0; i < n; i++) {
        printf("P%d | ", i);
        while (p[i].burst_time > 0) {
            current_time++;
            p[i].burst_time--;
            printf("%d ", current_time);
            if (p[i].burst_time == 0) {
                p[i].turnaround_time = current_time - p[i].arrival_time;
                p[i].waiting_time = p[i].turnaround_time - p[i].burst_time;
                printf("| ");
            }
            for (j = i + 1; j < n; j++) {
                if (p[j].arrival_time <= current_time && p[j].priority > p[i].priority) {
                    temp = p[i];
                    p[i] = p[j];
                    p[j] = temp;
                    i--;
                    break;
                }
            }
        }
        printf("\n");
    }
    printf("Process\tTurnaround Time\tWaiting Time\n");
    for (i = 0; i < n; i++) {
        printf("P%d\t%d\t\t%d\n", i, p[i].turnaround_time, p[i].waiting_time);
    }
    int total_turnaround_time = 0, total_waiting_time = 0;
    for (i = 0; i < n; i++) {
        total_turnaround_time += p[i].turnaround_time;
        total_waiting_time += p[i].waiting_time;
    }
    printf("Average Turnaround Time: %.2f\n", (float)total_turnaround_time / n);
    printf("Average Waiting Time: %.2f\n", (float)total_waiting_time / n);
}
 int main() {
    int n;
    printf("Enter the number of processes: ");
    scanf("%d", &n);
    Process p[n];
    for (int i = 0; i < n; i++) {
        printf("Enter arrival time, burst time, and priority for process P%d: ", i);
        scanf("%d %d %d", &p[i].arrival_time, &p[i].burst_time, &p[i].priority);
    }
    srand(time(NULL)); 
    preemptive_priority_scheduling(p, n);

    return 0;
    }