Question

1.      Write a C or C++ program A6p2.c[pp] that accepts one command line argument which is an integer n between 2 and 4 inclusive. Generate 60 random integers between 1 and 39 inclusive and store them in a 5 by 12 two dimensional integer array (e.g.,int a[5][12];). Use pthread to create n threads to convert all 60 array elements modulo 11 (i.e. take the remainder after division by 11) in place. You should divide this update task among the n threads as evenly as possible. Print the array both before and after the update separately as 5 by 12 matrices. Hint: it is dangerous to have code to print messages in your thread function(s). Note: if you do not use pthread to divide the update task among the threads, you may get zero points. A sample run of the programs in 1 and 2 is shown below. You do NOT need to submit screen shots. Instead submit your source files.

[kwang@computer][~/work/]$ ./A6p1 3 60

using 3 threads to handle 60 chars.

original random upper case string:

RUIQWCXXBFXVZFJDBWTSIBFIMMJJNRKENUUJZUIABIYANHFQDZINCPVOCGAP

off-by-one lower case string:

svjrxdyycgywagkecxutjcgjnnkkoslfovvkavjbcjzboigreajodqwpdhbq

[kwang@computer][~/work/]$ ./A6p2 4

using 4 threads.

original array:

33           36            9               30            1               29            14            16            7               34            6               18            

14           2               34            11            18            11            6               17            34            33            16            35            

26           11            17            13            27            39            22            21            24            19            11            25            

9              24            29            15            7               35            21            9               25            16            20            3               

26           14            19            9               7               24            4               21            34            9               33            22            

updated array:

0               3               9               8               1               7               3               5               7               1               6               7               

3               2               1               0               7               0               6               6               1               0               5               2               

4               0               6               2               5               6               0               10            2               8               0               3               

9               2               7               4               7               2               10            9               3               5               9               3               

4               3               8               9               7               2               4               10            1               9               0               0

Answer 1

#include <iostream>

#include <cstdlib>

#include <pthread.h>

using namespace std;

#define COLS 12 //column size

#define ROWS 5 //row size

int SIZE_REQ;

int arr[ROWS][COLS] ;

//matrix of sqaures creation using threads

void *SQUAREMATRIX(void *threadid) {

  long tid;

  

  tid = (long)threadid;

  

  int start = tid * SIZE_REQ;

  int end=start+SIZE_REQ-1;

  for(int i=0; i<ROWS; i++){

    

    for(int j=0;j<COLS;j++){

      

      int Pos_REQ = i*COLS + j;

      

      if(Pos_REQ>=start&&Pos_REQ<=end)

        {

          arr[i][j]=arr[i][j]*arr[i][j];

        }

    }

    

  }

  

  pthread_exit(NULL);

}

int main ()

{

  int n=0;

  

  cin>>n;

  if(n<=4 && n>=2)

    {

      pthread_t threads[n];

      int rc;

      long i,j;

      

      

      //loading array with data

      for(i=0;i<ROWS;i++)

        {

          for(j=0;j<COLS;j++)

            {

              arr[i][j]=(rand() % 49) + 1;

            }

        }

      

      

      //displaying Array in random

      for(i=0;i<ROWS;i++)

        {

          cout<<"\n";

          for(j=0;j<COLS;j++)

            {

              cout<<arr[i][j]<<"\t";

            }

        }

      

      SIZE_REQ = (60 + n - 1) / n; // divide by threads rounded up.

      

      

      

      

      for( i = 0; i < n; i++ ) {

        cout << "\nmain() : creating thread, " << i << endl;

        rc = pthread_create(&threads[i], NULL, SQUAREMATRIX, (void *)i);

        

        if (rc) {

          cout << "Error:unable to create thread," << rc << endl;

          exit(-1);

        }

      }

      //Printing Resulter Array

      for(i=0;i<ROWS;i++)

        {

          cout<<"\n";

          for(j=0;j<COLS;j++)

            {

              cout<<arr[i][j]<<"\t";

            }

        }

      pthread_exit(NULL);

    }

  else

    cout<<"invalid command"; //if input is wrong

}