#include <upc_relaxed.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>

#define TOTALSIZE   800

//== declare the x, x_new, b arrays in the shared space with size of TOTALSIZE
shared double x[TOTALSIZE];
shared double x_new[TOTALSIZE];
shared double b[TOTALSIZE];

void init();

int main(int argc, char **argv){
     int j;

     init();
     upc_barrier;

     //== add a for loop which goes through the elements in the x_new array
     for( j=0; j<(TOTALSIZE)-1; j++ ){
         //== insert an if statement to do the work sharing across the threads
         if(THREADS == MYTHREAD){
             x_new[j] = 0.5*( x[j-1] + x[j+1] + b[j] );
         }
     }

     if( MYTHREAD == 0 ){
         printf("   b   |    x   | x_new\n");
         printf("=============================\n");

         for( j=0; j<TOTALSIZE; j++ )
             printf("%1.4f | %1.4f | %1.4f \n", b[j], x[j], x_new[j]);
     }

     return 0;
 }

 void init(){
     int i;

     if( MYTHREAD == 0 ){
         srand(time(NULL));

         for( i = 0; i<TOTALSIZE; i++ ){
             b[i] = (double)rand() / RAND_MAX;
             x[i] = (double)rand() / RAND_MAX;
         }
     }
}