Modify and run the program shown below in the following way. There is an array of 20 elements defined in the program. The elements of the array are: [20 18 16 14 12 10 8 6 4 2 -20 -18 -16 -14 -12 -10 -8 -6 -4 -2]. Thread 1 adds the first five elements [20, 18, 16, 14, 12], Thread 2 adds the next five elements [10, 8, 6, 4, 2], ..., Thread 4 adds the last five elements [-10 -8 -6 -4 -2]. Finally, the sum of all the 20 elements is printed by the main program. include #include #include #define NUM_THREADS 3 int counter=1;

void *PrintHello(void *threadid) { counter = 2*counter+ (int) threadid; printf(" Thread Id: %d Counter: %d ", threadid, counter); pthread_exit(NULL); } int main(int argc, char *argv[]) { pthread_t threads[NUM_THREADS]; int rc, t; for(t=0;t