#include <stdio.h>

#define ARRAYSIZE  17
#define NUMTHREADS  4

/* puts i^2 into array positions i=start to stop-1 */
void* squarer(int start, int stop, int* array) {
    int i;
    
    for (i=start; i<stop; i++) {
        array[i]=i*i;
    }
    
    return NULL;    
}

int main(void) {
    int array[ARRAYSIZE];
    int i, start, stop;
    /*
      this has the effect of rounding up the number of tasks
      per thread, which is useful in case ARRAYSIZE does not
      divide evenly by NUMTHREADS.
    */
    int tasksPerThread=(ARRAYSIZE+NUMTHREADS-1)/NUMTHREADS;

    
    /* Do the loop in NUMTHREADS pieces */
    for (i=0; i<NUMTHREADS; i++) {
    	start=i*tasksPerThread;
    	stop=(i+1)*tasksPerThread;
    	/* if the tasks do not divide evenly, we could have stop too big.  Check and fix. */
    	if (stop>ARRAYSIZE) {
    	    stop=ARRAYSIZE;
    	}
        squarer(start, stop, array);
    }
    
    /* Display Result */
    for (i=0; i<ARRAYSIZE; i++) {
        printf("%d ", array[i]);
    }
    printf("\n");
    
    return 0;
}