#include <omp.h>static long num_steps = 100000;double step; #define NUM_THREADS 4 void main () {	  int i; 	  	  double x, pi, sum[NUM_THREADS]; 	  step = 1.0/(double) num_steps; 	  omp_set_num_threads(NUM_THREADS); 	 #pragma omp parallel 	 {	  		double x;     		int id; 	  	id = omp_get_thread_num(); 	  	for (i=id, sum[id]=0.0;i< num_steps; i=i+NUM_THREADS){ 		  	x = (i+0.5)*step; 		  	sum[id] += 4.0/(1.0+x*x); 	  	} 	 } 	  for(i=0, pi=0.0;i<NUM_THREADS;i++)pi += sum[i] * step; 	  printf("Pi = %lf\n",pi);}