select first process arrived, sjf in scheduling process

Question

empror9 0 Junior Poster in Training

11 Years Ago

hello,

i'm writing a code for non-preemptive shortest job first, everything is okay except to select the first process arrived in the queue. here is my code.

#include<iostream>
using namespace std;

struct process{
    int processId;
    int burstTime;
    int arrivalTime;
};

int main(){
    int numberOfProcesses;

     //number of process
    cout <<"please enter the number of process: ";
    cin >> numberOfProcesses;

    struct process p[numberOfProcesses];
    struct process temp;


     // get burst time , arrival time
     for(int i=0; i<numberOfProcesses; i++){
        p[i].processId = i;
        cout << "p" << i << ":" << endl;
        cout <<"Burst time: ";
        cin >> p[i].burstTime;
        cout <<"Arrival Time: ";
        cin >> p[i].arrivalTime;
      }

       //display user input
       cout<<"Process" << "\t" << "Burst" << "\t" << "Arrival" << endl;
      for(int i=0;i<numberOfProcesses;i++){
          cout <<"P" << p[i].processId << "\t" << p[i].burstTime << "\t" << p[i].arrivalTime <<endl;
      }

      int arrivedFirst;
      //sort
      for(int i=0; i<numberOfProcesses; i++){
          for(int j=0; j<numberOfProcesses; j++){
            for(int arrival=1; arrival<numberOfProcesses; arrival++){
            arrivedFirst = p[0].arrivalTime;
                if(p[arrival].arrivalTime<arrivedFirst){
                    arrivedFirst = p[arrival].arrivalTime;

                }
            }
              // select the arrived proccess first
              if(arrivedFirst){

              }
              // select the smallest burst time
              if(p[j].burstTime>p[i].burstTime){
                  temp = p[i];
                  p[i] = p[j] ;
                  p[j] = temp;
              }
              // if same value with burst time, select the arrived first
              if(p[j].burstTime==p[i].burstTime){
                  if(p[j].arrivalTime>p[i].arrivalTime){
                  temp = p[i];
                  p[i] = p[j] ;
                  p[j] = temp;
                  }
              }
          }
      }

     // after computing

      //display
      cout << endl;
       cout<<"Process" << "\t" << "Burst" << "\t" << "Arrival" << endl;
      for(int i=0;i<numberOfProcesses;i++){
          cout <<"P" << p[i].processId << "\t" << p[i].burstTime << "\t" << p[i].arrivalTime <<endl;
      }

      return 0;
      }

the missing code is in line 48.

c++

Edited 11 Years Ago by empror9

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15 Replies
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Latest Post 11 Years Ago Latest Post by empror9

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Ancient Dragon 5,243 Achieved Level 70

11 Years Ago

What exactly do you want that if statement to do?

Ancient Dragon 5,243 Achieved Level 70

11 Years Ago

Its not necessary to sort the array because you can sort on only one of the structure members. Just delete all that code from lines 39 to 66, its wrong anyway.

Instead of sorting, just loop through the array and find the indices with the smallest value. Do you know how to do that with a simple integer array? If yes, then this should be a piece of cake for you because its the same idea, except that you need to find two values, not just one. You will need 2 integers, one to hold the index of where the smallest burst time was found, and the other to find the index of where the smallest time was found. You can find both values in the same loop.

Edited 11 Years Ago by Ancient Dragon

triumphost 120 Posting Whiz

11 Years Ago

int Smallest(int Array[], int size)
{
    if (size == 1)                  
        return Array[0];

    int A = Array[0];                  
    for (int I = 0; I < size; I++)     
        A = Array[I] < A ? Array[I] : A;

    return A;
}


int Smallest(std::vector<int> Array)
{
    if (Array.size() == 1)
        return Array[0];

    int A = Array[0];
    for (int I = 0; I < Array.size(); I++)
        A = Array[I] < A ? Array[I] : A;

    return A;
}

Ancient Dragon 5,243 Achieved Level 70

11 Years Ago

struct process{
    int processId;
    int burstTime;
    int arrivalTime;
};
const int maxprocesses = 10;
struct process p[maxprocesses];

...
...
// initialize variables
int smallest_burst = p[0].burstTime;
int smallest_burst_index = 0;
int smallest_arrivalTime = p[0].arrivalTime;
int smallest_arrivalTime_index = 0;

for(int i = 1; i < maxprocesses; ++i)
{
   if( p[i].burstTime < smallest_burst)
   {
       smallest_burst = p[i].burstTime;
       smallest_burst_index = i;

   }
   // now do the same test for arrivalTime
}

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empror9 0 Junior Poster in Training · Answer 1 · 2012-07-23T12:03:57+00:00

ok, I want first to select the first process according to the first arrived time, in other words, the smallest arrival time must be seleced, then I want select the rest according to the smallest burst time.

here is my code now.

#include<iostream>
using namespace std;

struct process{
    int processId;
    int burstTime;
    int arrivalTime;
    // int arrivedFirst;
};

int main(){
    int numberOfProcesses;

     //number of process
    cout <<"please enter the number of process: ";
    cin >> numberOfProcesses;

    struct process p[numberOfProcesses];
    struct process temp;


     // get burst time , arrival time
     for(int i=0; i<numberOfProcesses; i++){
        p[i].processId = i;
        cout << "p" << i << ":" << endl;
        cout <<"Burst time: ";
        cin >> p[i].burstTime;
        cout <<"Arrival Time: ";
        cin >> p[i].arrivalTime;
      }

       //display user input
       cout<<"Process" << "\t" << "Burst" << "\t" << "Arrival" << endl;
      for(int i=0;i<numberOfProcesses;i++){
          cout <<"P" << p[i].processId << "\t" << p[i].burstTime << "\t" << p[i].arrivalTime <<endl;
      }


      //sort
      for(int i=0; i<numberOfProcesses; i++){
          for(int j=0; j<numberOfProcesses; j++){
            for(int arrival=1; arrival<numberOfProcesses; arrival++){
            p[i].arrivalTime = p[0].arrivalTime;
                if(p[arrival].arrivalTime<p[j].arrivalTime){
                    p[0].arrivalTime = p[arrival].arrivalTime;

                }
            }

              // select the smallest burst time
              if(p[j].burstTime>p[i].burstTime){
                  temp = p[i];
                  p[i] = p[j] ;
                  p[j] = temp;
              }
              // if same value with burst time, select the arrived first
              if(p[j].burstTime==p[i].burstTime){
                  if(p[j].arrivalTime>p[i].arrivalTime){
                  temp = p[i];
                  p[i] = p[j] ;
                  p[j] = temp;
                  }
              }
          }
      }

     // after computing

      //display
      cout << endl;
       cout<<"Process" << "\t" << "Burst" << "\t" << "Arrival" << endl;
      for(int i=0;i<numberOfProcesses;i++){

          cout <<"P" << p[i].processId << "\t" << p[i].burstTime << "\t" << p[i].arrivalTime <<endl;
      }

      return 0;
      }

empror9 0 Junior Poster in Training · Answer 2 · 2012-07-23T19:26:28+00:00

Ancient Dragon could you please explain more in codes? thanks

empror9 0 Junior Poster in Training · Answer 3 · 2012-07-28T00:21:41+00:00

please see my code now

#include<iostream>
using namespace std;

struct process{
    int processId;
    int burstTime;
    int arrivalTime;
};

int main(){
    int numberOfProcesses;

     //number of process
    cout <<"please enter the number of process: ";
    cin >> numberOfProcesses;
    const int maxprocesses = 10;
    struct process p[maxprocesses];



    // initialize variables
    int smallest_burst = p[0].burstTime;
    int smallest_burst_index = 0;
    int smallest_arrivalTime = p[0].arrivalTime;
    int smallest_arrivalTime_index = 0;



     // get burst time , arrival time
     for(int i=0; i<numberOfProcesses; i++){
        p[i].processId = i;
        cout << "p" << i << ":" << endl;
        cout <<"Burst time: ";
        cin >> p[i].burstTime;
        cout <<"Arrival Time: ";
        cin >> p[i].arrivalTime;
      }

       //display user input
      cout<<"Process" << "\t" << "Burst" << "\t" << "Arrival" << endl;
      for(int i=0;i<numberOfProcesses;i++){
          cout <<"P" << p[i].processId << "\t" << p[i].burstTime << "\t" << p[i].arrivalTime <<endl;
      }



     // after computing
     for(int i = 1; i < maxprocesses; ++i)
    {
       if(p[i].burstTime < smallest_burst)
       {
           smallest_burst = p[i].burstTime;
           smallest_burst_index = i;
       }

        if(p[i].arrivalTime < smallest_arrivalTime)
       {
           smallest_arrivalTime = p[i].arrivalTime;
           smallest_arrivalTime_index = i;
       }
    }

      //display
      cout << endl;
      cout<<"Process" << "\t" << "Burst" << "\t" << "Arrival" << endl;
      for(int i=0;i<numberOfProcesses;i++){
      // here i want to print the smallest arrivaltime first,
      // as you see i write like below but doen't work. 

          if(smallest_arrivalTime)
          {
            cout <<"P" << smallest_arrivalTime_index << "\t" << p[i].burstTime << "\t" << smallest_arrivalTime <<endl;

          }
            cout <<"P" << p[i].processId << "\t" << p[i].burstTime << "\t" << p[i].arrivalTime <<endl;
      }

      return 0;
      }

please see line 69

empror9 0 Junior Poster in Training · Answer 4 · 2012-07-29T02:25:56+00:00

empror9 0 Junior Poster in Training

11 Years Ago

i'm still waiting for a help :)

Ancient Dragon 5,243 Achieved Level 70 Team Colleague Featured Poster · Answer 5 · 2012-07-29T02:57:48+00:00

display it like thiks example: smallest arrival time is
p[smallest_arrivalTime_index].arrivalTime;

Also -- delete the loop on line 66 and if statement on line 70, there is no reason for them. All you want left there is line 72 and line 75.

empror9 0 Junior Poster in Training · Answer 6 · 2012-08-01T13:59:43+00:00

Ancient Dragon I want first to select the first process that arrive ((lowest arrival must be selected))

after that, i must select process based on shorter burst time. that's it

becuase i think you didn't understand my question very well :)

Ancient Dragon 5,243 Achieved Level 70 Team Colleague Featured Poster · Answer 7 · 2012-08-01T14:32:07+00:00

If you want to show all processes in ascending order by burst time then sort them by burst time. No need to sort by arrival time, just get it as previously posted.

cout << "Sortest Arrival Time: " << p[smallest_arrivalTime_index].arrivalTime << '\n';
cout << "Burst Times: \n";
for(int i = 0; i < maxprocesses; ++i)
{
   if( i != smallest_arrivalTime_index )
       cout << p[i].burstTime << '\n';///

}

empror9 0 Junior Poster in Training · Answer 8 · 2012-08-02T12:41:15+00:00

please see the result.

this is all the code

#include<iostream>
using namespace std;

struct process{
    int processId;
    int burstTime;
    int arrivalTime;
};

int main(){
    int numberOfProcesses;

     //number of process
    cout <<"please enter the number of process: ";
    cin >> numberOfProcesses;
    const int maxprocesses = 10;
    struct process p[maxprocesses];



    // initialize variables
    int smallest_burst = p[0].burstTime;
    int smallest_burst_index = 0;
    int smallest_arrivalTime = p[0].arrivalTime;
    int smallest_arrivalTime_index = 0;



     // get burst time , arrival time
     for(int i=0; i<numberOfProcesses; i++){
        p[i].processId = i;
        cout << "p" << i << ":" << endl;
        cout <<"Burst time: ";
        cin >> p[i].burstTime;
        cout <<"Arrival Time: ";
        cin >> p[i].arrivalTime;
      }

       //display user input
      cout<<"Process" << "\t" << "Burst" << "\t" << "Arrival" << endl;
      for(int i=0;i<numberOfProcesses;i++){
          cout <<"P" << p[i].processId << "\t" << p[i].burstTime << "\t" << p[i].arrivalTime <<endl;
      }



     // after computing
     for(int i = 1; i < maxprocesses; ++i)
    {
       if(p[i].burstTime < smallest_burst)
       {
           smallest_burst = p[i].burstTime;
           smallest_burst_index = i;
       }

        if(p[i].arrivalTime < smallest_arrivalTime)
       {
           smallest_arrivalTime = p[i].arrivalTime;
           smallest_arrivalTime_index = i;
       }
    }

      //display
      cout << endl;
    //  cout<<"Process" << "\t" << "Burst" << "\t" << "Arrival" << endl;
      cout << "Sortest Arrival Time: " << p[smallest_arrivalTime_index].arrivalTime << '\n';
        cout << "Burst Times: \n";
        for(int i = 0; i < maxprocesses; ++i)
        {
           if( i != smallest_arrivalTime_index )
               cout << p[i].burstTime << '\n';///

        }



      return 0;
      }

Ancient Dragon 5,243 Achieved Level 70 Team Colleague Featured Poster · Answer 9 · 2012-08-02T13:40:11+00:00

You are very close -- only five problems marked with // <<<< in the code below

#include<iostream>
using namespace std;

struct process{
    int processId;
    int burstTime;
    int arrivalTime;
};

int main(){
    int numberOfProcesses;
    const int maxprocesses = 10;        //<<<<<<< these two lines were declared in the wrong place
    struct process p[maxprocesses];     //<<<<<<< ^^^^

     //number of process
    cout <<"please enter the number of process: ";
    cin >> numberOfProcesses;



    // initialize variables
    int smallest_burst = p[0].burstTime;
    int smallest_burst_index = 0;
    int smallest_arrivalTime = 0;
    int smallest_arrivalTime_index = 0; // <<<< Can not be initialized here



     // get burst time , arrival time
     for(int i=0; i<numberOfProcesses; i++){
        p[i].processId = i;
        cout << "p" << i << ":" << endl;
        cout <<"Burst time: ";
        cin >> p[i].burstTime;
        cout <<"Arrival Time: ";
        cin >> p[i].arrivalTime;
      }
    smallest_arrivalTime = p[0].arrivalTime; // <<<<<< Initialize variable

       //display user input
      cout<<"Process" << "\t" << "Burst" << "\t" << "Arrival" << endl;
      for(int i=0;i<numberOfProcesses;i++){
          cout <<"P" << p[i].processId << "\t" << p[i].burstTime << "\t" << p[i].arrivalTime <<endl;
      }



     // after computing
    for(int i = 1; i < numberOfProcesses; ++i) // <<<<<<<<<<<<<
    {
       if(p[i].burstTime < smallest_burst)
       {
           smallest_burst = p[i].burstTime;
           smallest_burst_index = i;
       }

        if(p[i].arrivalTime < smallest_arrivalTime)
       {
           smallest_arrivalTime = p[i].arrivalTime;
           smallest_arrivalTime_index = i;
       }
    }

      //display
      cout << endl;
    //  cout<<"Process" << "\t" << "Burst" << "\t" << "Arrival" << endl;
      cout << "Sortest Arrival Time: " << p[smallest_arrivalTime_index].arrivalTime << '\n';
        cout << "Burst Times: \n";
        for(int i = 0; i < numberOfProcesses; ++i) // <<<<<<<<<<<<<
        {
           if( i != smallest_arrivalTime_index )
               cout << p[i].burstTime << '\n';///

        }



      return 0;
      }

empror9 0 Junior Poster in Training · Answer 10 · 2012-08-13T02:04:44+00:00

i'm sorry i'm late. I really don't know how to correct the code. can you do it for me?

becuase I think the mistakes are so easy :)

thank you

empror9 0 Junior Poster in Training · Answer 11 · 2012-08-15T19:13:34+00:00

empror9 0 Junior Poster in Training

11 Years Ago

please any one can help?

select first process arrived, sjf in scheduling process

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