Scheduling in Operating Systems (2025 Guide): From Classic Algorithms to AI-Enhanced Schedulers

				
					#include <stdio.h>

int main() {
    int n, i, time_quantum, total = 0, x, counter = 0;
    int wait_time = 0, turnaround_time = 0;
    int arrival_time[10], burst_time[10], temp_burst_time[10];

    printf("Enter the total number of processes: ");
    scanf("%d", &n);
    x = n;

    for(i = 0; i < n; i++) {
        printf("\nEnter arrival time of process %d: ", i + 1);
        scanf("%d", &arrival_time[i]);
        printf("Enter burst time of process %d: ", i + 1);
        scanf("%d", &burst_time[i]);
        temp_burst_time[i] = burst_time[i]; // store burst times in temp
    }

    printf("\nEnter the time quantum: ");
    scanf("%d", &time_quantum);

    printf("\nProcess\tBurst Time\tWaiting Time\tTurnaround Time");

    int time = 0;
    for(total = 0, i = 0; x != 0;) {
        if(temp_burst_time[i] > 0 && temp_burst_time[i] <= time_quantum) {
            time += temp_burst_time[i];
            temp_burst_time[i] = 0;
            counter = 1;
        } else if(temp_burst_time[i] > 0) {
            temp_burst_time[i] -= time_quantum;
            time += time_quantum;
        }

        if(temp_burst_time[i] == 0 && counter == 1) {
            x--;
            int wt = time - arrival_time[i] - burst_time[i];
            int tat = time - arrival_time[i];

            printf("\nP%d\t%d\t\t%d\t\t%d", i + 1, burst_time[i], wt, tat);

            wait_time += wt;
            turnaround_time += tat;
            counter = 0;
        }

        // Move to next process
        if(i == n - 1)
            i = 0;
        else if(arrival_time[i + 1] <= time)
            i++;
        else
            i = 0;
    }

    float avg_wait = (float)wait_time / n;
    float avg_turnaround = (float)turnaround_time / n;

    printf("\n\nAverage Waiting Time: %.2f", avg_wait);
    printf("\nAverage Turnaround Time: %.2f\n", avg_turnaround);

    return 0;
}