Question

using C coding

write a program that takes the numbers from the array {1,2,3,4,5,6,7,8,9,10} and uses 2 threads at the same time. One thread will find the addition of the numbers, and the other will find the multiplication of the numbers. The two different threads will run at the same time and will have an end run of:

the addition is: 55

the multiplication is: 3628800

Answer 1

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h> //Header file for sleep(). man 3 sleep for details.
#include <pthread.h>

// size of array
#define MAX 16

// maximum number of threads
#define MAX_THREAD 4


int a[] = { 1,2,3,4,5,6,7,8,9,10 };
int sum=0;
int mul=1;
void* sum_array(void* arg)
{

// Each thread computes sum of 1/4th of array

for (int i =0;i<10; i++)
sum =sum+a[i];
}

void* mul_array(void* arg)
{

// Each thread computes sum of 1/4th of array

for (int i =0;i<10; i++){
mul =mul* a[i];
}
}

// Driver Code
int main()
{

pthread_t threads[2];

// Creating 4 threads

pthread_create(&threads[0], NULL, sum_array, (void*)NULL);


pthread_join(threads[0], NULL);

pthread_create(&threads[1], NULL, mul_array, (void*)NULL);


pthread_join(threads[1], NULL);



printf("the addition is: %d\n",sum);
printf("the multiplication is %d\n",mul);



return 0;
}

===================================

akshay@akshay-Inspiron-3537:~/CODE$ gcc pthread.c -pthread
akshay@akshay-Inspiron-3537:~/CODE$ ./a.out
the addition is: 55
the multiplication is 3628800