Question

Write a C or C++ program A6p1.c[pp] that accepts two command line arguments n and m where n is an integer between 2 and 6 inclusive and m can be assumed to be a multiple of 60 (e.g. 60,120,etc). Generate a string of m random upper case English characters and store them somewhere (e.g. in a char array). Use pthread to create n threads to convert the string of m chars in place into an off-by-one lower case version (i.e. ‘A’→’b’, ‘B’→’c’, ‘C’→’d’,…, ‘Y’→’z’, ‘Z’→’a’). You should divide this conversion task among the n threads as evenly as possible. Print out the string both before and after conversion on two separate lines. Hint: it is dangerous to have code to print messages in your thread function(s). You may refer to testThread.c, testThread2.c, pthread_ex1.c, pthread_ex2.c for examples. Note: if you do not use pthread to divide the conversion task among the threads, you may get zero points.

Has to contain two line arguments, not just one.

Answer 1

/ CPP Program to find sum of array

#include <iostream>

#include <pthread.h>

#include <cstdlib>

#include <stdio.h>

// size of array

#define MAX 60

using namespace std;

char a[MAX];

int part = 0;

int MAX_THREAD;

void *convert_to_lowercase(void *arg)

{

   

   // Each thread will convert 1/MAX_THREAD part of the array

   int thread_part = part++;

   

   for (int i = thread_part *(MAX / MAX_THREAD); i < (thread_part + 1) *(MAX / MAX_THREAD); i++)

      {

         //if the character is Z then it should be converted to a

         if (a[i] == 90)

            a[i] = 97;

         else

            a[i] = a[i] + 33;

      }

}

// Driver Code

int main(int argc, char **argv)

{

   if (argc == 2)

      sscanf(argv[1], "%d", &MAX_THREAD);

   else

      {

         cout << "The number of arguments is invalid" << endl;

         return -1;

      }

   if (MAX_THREAD < 3 || MAX_THREAD > 5)

      {

         cout << "The number of threads is invalid" << endl;

         return -1;

      }

   for (int i = 0; i < MAX; i++)

      //create a string of random upper case characters and storing it in an char array

   a[i] = (char)(64 + rand() % 26 + 1);

   cout << "The String before conversion is: " << endl;

   //print the string with random characters

   for (int i = 0; i < MAX; i++)

      cout << a[i];

   cout << endl;

   pthread_t threads[MAX_THREAD];

   

   // Creating 4 threads

   for (int i = 0; i < MAX_THREAD; i++)

      pthread_create(&threads[i], NULL, convert_to_lowercase, (void*) NULL);

   

   // joining 4 threads i.e. waiting for all 4 threads to complete

   for (int i = 0; i < MAX_THREAD; i++)

      pthread_join(threads[i], NULL);

   cout << "The String after conversion is: " << endl;

   for (int i = 0; i < MAX; i++)

      cout << a[i];

   cout << endl;

   return 0;

}