elevator_simulator_v1.c

/*

    elevator_simulator_v1.c     by Dragan Milicev

    Task from Alberto Valles:
    https://web.facebook.com/alberto.valles.3720

    https://web.facebook.com/photo/?fbid=641103200120496&set=gm.1679083448917165

Try:
Enter next floors separated by commas or 0 to exit: 3,12,5,15,0


To start the simulation, the Elevator Simulator (ES) must prompt for a starting floor.

After this, for each visited floor, the ES must display the floor number and the state
of the door and the car.

When the car gets to a destination floor, the ES must stop the car, open the door
and prompt for the next floors.

A floor zero input must stop the simulation.

A multiple floor input must be a comma-separated list.

The ES must visit requested floors by getting to the furthest floor in the current
car direction before reversing direction to visit pending floors as necessary.

An empty next floor input must be ignored when no floors are pending.

Otherwise, the door must close and the car must start moving toward the next floor.

Here is an example of interaction with the ES:


 Welcome to the Elevator Simulator by M.E.E.E. Engineering

 Starting Floor: 7

 1 Floor 7       Door: Open      Car: Stopped

 Enter next floors separated by commas or 0 to exit: 9

 Floor 8         Door: Closed   Car: Moving Up

 3 Floor 9       Door: Open      Car: Stopped

 Enter next floors separated by commas or 0 to exit: 0

 Thank you for using the Elevator Simulator  by M.E.E.E. Engineering.



    You can find all my C programs at Dragan Milicev's pastebin:

    https://pastebin.com/u/dmilicev

*/

#include <stdio.h>
#include <string.h>

#define STR_SIZE 1024

// function bubbleSort to sort the array in descending order
void bubbleSort(int arr[], int n)
{
    int i, j, temp;

    for (i = 0; i < n-1; i++)
        for (j = 0; j < n-i-1; j++)     // Last i elements are already in place
            if (arr[j] < arr[j+1])      // arr[j] > arr[j+1] for ascending order
            {
                temp = arr[j];
                arr[j] = arr[j+1];
                arr[j+1] = temp;
            }
} // bubbleSort()

/*
1. Read the entire line in a buffer
2. Separate in tokens by “,”
3. For each token, call atoi(token)
4. Sort array in descending order by calling bubbleSort()
5. Return length, number of integers in array
*/
int enter_next_floors(int array[])
{
    int length=0;
    char buffer[STR_SIZE];
    char *aux;

    printf("\n Enter next floors separated by commas or 0 to exit: ");
    fgets(buffer,STR_SIZE-1,stdin);

    aux = strtok(buffer, ",");
    while(aux)
    {
        array[length] = atoi(aux);
        length++;
        aux = strtok(NULL, ",");
    }

    bubbleSort(array,length);

    return length;
} // enter_next_floors()


int main(void)
{
    int starting_floor=7, next_floor=0;
    int floors[STR_SIZE];
    int num_of_floors=0;
    int i;

    printf("\n Welcome to the Elevator Simulator by M.E.E.E. Engineering \n");
    printf("\n Starting Floor: %d \n", starting_floor);
    printf("\n Floor %d \t Door: Open \t Car: Stopped \n", starting_floor);

    while(1)
    {
        num_of_floors = enter_next_floors(floors);

        for(i=0;i<num_of_floors;i++)
        {
            if(floors[i]==0)                        // Exit of Simulation
            {
                printf("\n Thank you for using the Elevator Simulator by M.E.E.E. Engineering. \n");
                return 0;
            }

            if(floors[i]<starting_floor)            // Moving Down
            {
                while(floors[i]<starting_floor-1)
                {
                    starting_floor--;
                    printf("\n Floor %d \t Door: Closed \t Car: Moving Down \n", starting_floor);
                }
                starting_floor--;
                printf("\n Floor %d \t Door: Open \t Car: Stopped \n", starting_floor);
            }
            else if(floors[i]>starting_floor)       // Moving Up
            {
                while(floors[i]>starting_floor+1)
                {
                    starting_floor++;
                    printf("\n Floor %d \t Door: Closed \t Car: Moving Up \n", starting_floor);
                }
                starting_floor++;
                printf("\n Floor %d \t Door: Open \t Car: Stopped \n", starting_floor);
            }
            else    // floors[i] == starting_floor
            {
                printf("\n You are already on Floor: %d \n", starting_floor);
            }

        } // for(i=0;i<num_of_floors;i++)

    } // while(1)

    return 0;   // Unnecessary line of code, will never be executed.
} // main()