RoundRobin.c

#include <stdio.h>
#include <stdlib.h>
typedef struct {
    int id, et, at, rt, ct, wt, tat;
} Task;
void roundRobin(Task tasks[], int n, int tq) {
    int queue[100], front = 0, rear = -1;
    int time = 0, completed = 0;
    int visited[100] = {0};
    for(int i = 0; i < n; i++) {
        tasks[i].rt = tasks[i].et;
    }
    printf("Execution Order:\n");
    int first = 1;
    for(int i = 0; i < n; i++) {
        if(tasks[i].at == 0) {
            queue[++rear] = i;
            visited[i] = 1;
            break;
        }
    }
    while(completed < n) {
        if(front <= rear) {
            int idx = queue[front++];
            
            if(!first) printf(" → ");
            printf("%d", tasks[idx].id);
            first = 0;
            
            int exec_time = (tasks[idx].rt < tq) ? tasks[idx].rt : tq;
            tasks[idx].rt -= exec_time;
            time += exec_time;
            for(int i = 0; i < n; i++) {
                if(tasks[i].at <= time && !visited[i] && tasks[i].rt > 0) {
                    queue[++rear] = i;
                    visited[i] = 1;
                }
            }
            
            if(tasks[idx].rt == 0) {
                tasks[idx].ct = time;
                tasks[idx].tat = tasks[idx].ct - tasks[idx].at;
                tasks[idx].wt = tasks[idx].tat - tasks[idx].et;
                completed++;
            } else {
                queue[++rear] = idx;
            }
        } else {
            time++;
            for(int i = 0; i < n; i++) {
                if(tasks[i].at == time && !visited[i]) {
                    queue[++rear] = i;
                    visited[i] = 1;
                }
            }
        }
    }
    
    printf("\n\nCompletion Times:\n");
    for(int i = 0; i < n; i++) {
        printf("• Task %d: Cycle %d\n", tasks[i].id, tasks[i].ct);
    }
    
    printf("\nWaiting & Turnaround Times: (Printed in a table format)\n");
    printf("\n");
    printf("  Task     Waiting Time    Turnaround Time   \n");
    printf("\n");
    for(int i = 0; i < n; i++) {
        printf("    %d           %2d                %2d         \n", 
               tasks[i].id, tasks[i].wt, tasks[i].tat);
    }
    printf("\n");
}

int main() {
    int n, tq;
    
    printf("Enter number of tasks: ");
    scanf("%d", &n);
    
    printf("Enter time quantum: ");
    scanf("%d", &tq);
    
    Task tasks[n];
    
    printf("\nEnter task details:\n");
    for(int i = 0; i < n; i++) {
        printf("Task ID: ");
        scanf("%d", &tasks[i].id);
        printf("Execution Time: ");
        scanf("%d", &tasks[i].et);
        printf("Arrival Cycle: ");
        scanf("%d", &tasks[i].at);
        printf("\n");
    }
    
    printf("Input:\n");
    printf("Tasks = { ");
    for(int i = 0; i < n; i++) {
        printf("(ID=%d, ET=%d, AC=%d)", tasks[i].id, tasks[i].et, tasks[i].at);
        if(i < n-1) printf(", ");
    }
    printf(" }\n");
    printf("Time Quantum = %d\n\n", tq);
    
    printf("Output:\n");
    roundRobin(tasks, n, tq);
    
    return 0;
}