rr.c

#include <stdio.h>
#include <stdlib.h>

void calculateTimes(int n, int arrival[], int burst[], int waiting[], int turnaround[], int quantum) {
    int remaining_time[n];
    for (int i = 0; i < n; i++) {
        remaining_time[i] = burst[i]; // Initialize remaining time with burst time
    }

    int time = arrival[0]; // Start time is the arrival time of the first process
    int done = 0; // Number of completed processes

    while (done < n) {
        for (int i = 0; i < n; i++) {
            if (remaining_time[i] > 0 && arrival[i] <= time) {
                if (remaining_time[i] > quantum) {
                    // Process executes for the quantum time
                    time += quantum;
                    remaining_time[i] -= quantum;
                } else {
                    // Process completes execution
                    time += remaining_time[i];
                    waiting[i] = time - arrival[i] - burst[i];
                    turnaround[i] = time - arrival[i];
                    remaining_time[i] = 0;
                    done++;
                }
            }
        }
    }
}

void displayResults(int n, int pid[], int arrival[], int burst[], int waiting[], int turnaround[]) {
    float total_waiting = 0, total_turnaround = 0;
    printf("\nPID\tArrival\tBurst\tWaiting\tTurnaround\n");
    for (int i = 0; i < n; i++) {
        total_waiting += waiting[i];
        total_turnaround += turnaround[i];
        printf("P%d\t%d\t%d\t%d\t%d\n", pid[i], arrival[i], burst[i], waiting[i], turnaround[i]);
    }
    printf("\nAverage Waiting Time: %.2f", total_waiting / n);
    printf("\nAverage Turnaround Time: %.2f\n", total_turnaround / n);
}

void displayGanttChart(int n, int pid[], int arrival[], int burst[], int quantum) {
    printf("\nGantt Chart:\n");

    int remaining_time[n];
    for (int i = 0; i < n; i++) {
        remaining_time[i] = burst[i]; // Initialize remaining time with burst time
    }

    int time = arrival[0]; // Start time is the arrival time of the first process
    int done = 0; // Number of completed processes

    // Top border of the Gantt chart
    printf(" ");
    while (done < n) {
        for (int i = 0; i < n; i++) {
            if (remaining_time[i] > 0 && arrival[i] <= time) {
                if (remaining_time[i] > quantum) {
                    for (int j = 0; j < quantum; j++) printf("--");
                    printf(" ");
                    time += quantum;
                    remaining_time[i] -= quantum;
                } else {
                    for (int j = 0; j < remaining_time[i]; j++) printf("--");
                    printf(" ");
                    time += remaining_time[i];
                    remaining_time[i] = 0;
                    done++;
                }
            }
        }
    }
    printf("\n|");

    // Reset remaining_time and done for the process sequence
    for (int i = 0; i < n; i++) {
        remaining_time[i] = burst[i];
    }
    done = 0;
    time = arrival[0];

    // Process sequence in the Gantt chart
    while (done < n) {
        for (int i = 0; i < n; i++) {
            if (remaining_time[i] > 0 && arrival[i] <= time) {
                if (remaining_time[i] > quantum) {
                    printf(" P%d |", pid[i]);
                    time += quantum;
                    remaining_time[i] -= quantum;
                } else {
                    printf(" P%d |", pid[i]);
                    time += remaining_time[i];
                    remaining_time[i] = 0;
                    done++;
                }
            }
        }
    }
    printf("\n");

    // Bottom border of the Gantt chart
    printf(" ");
    for (int i = 0; i < n; i++) {
        remaining_time[i] = burst[i];
    }
    done = 0;
    time = arrival[0];

    while (done < n) {
        for (int i = 0; i < n; i++) {
            if (remaining_time[i] > 0 && arrival[i] <= time) {
                if (remaining_time[i] > quantum) {
                    for (int j = 0; j < quantum; j++) printf("--");
                    printf(" ");
                    time += quantum;
                    remaining_time[i] -= quantum;
                } else {
                    for (int j = 0; j < remaining_time[i]; j++) printf("--");
                    printf(" ");
                    time += remaining_time[i];
                    remaining_time[i] = 0;
                    done++;
                }
            }
        }
    }
    printf("\n");

    // Timeline below the Gantt chart
    time = arrival[0];
    done = 0;
    for (int i = 0; i < n; i++) {
        remaining_time[i] = burst[i];
    }

    printf("%d", time);
    while (done < n) {
        for (int i = 0; i < n; i++) {
            if (remaining_time[i] > 0 && arrival[i] <= time) {
                if (remaining_time[i] > quantum) {
                    time += quantum;
                    remaining_time[i] -= quantum;
                    printf("    %d", time);
                } else {
                    time += remaining_time[i];
                    remaining_time[i] = 0;
                    done++;
                    printf("    %d", time);
                }
            }
        }
    }
    printf("\n");
}

int main() {
    int n, quantum;
    printf("Enter number of processes: ");
    scanf("%d", &n);

    printf("Enter time quantum: ");
    scanf("%d", &quantum);

    int *arrival = (int *)malloc(n * sizeof(int));
    int *burst = (int *)malloc(n * sizeof(int));
    int *waiting = (int *)malloc(n * sizeof(int));
    int *turnaround = (int *)malloc(n * sizeof(int));
    int *pid = (int *)malloc(n * sizeof(int)); // Array to store process IDs

    for (int i = 0; i < n; i++) {
        printf("Enter arrival time and burst time for process %d: ", i + 1);
        scanf("%d %d", &arrival[i], &burst[i]);
        pid[i] = i + 1; // Assign process IDs (P1, P2, ...)
    }

    calculateTimes(n, arrival, burst, waiting, turnaround, quantum);
    displayResults(n, pid, arrival, burst, waiting, turnaround);
    displayGanttChart(n, pid, arrival, burst, quantum);

    free(arrival);
    free(burst);
    free(waiting);
    free(turnaround);
    free(pid);
    return 0;
}