pi_serial.c

//reference: https://gist.github.com/thinkphp/0d56dfd5eb5f91da029a91d4c7676f12
#include <stdlib.h>
#include <stdio.h>
#include <time.h>
#include <math.h>
 clock_t start, end;
int main(int argc, char*argv[])
{

    int n=atoi(argv[1]);
    double pi = 1.0;
    srand(time(NULL));
    int count=0;
    start = clock();
    for(int i=0;i<n;i++)
    {
        double x=(double)rand()/((double)RAND_MAX);
        double y=(double)rand()/((double)RAND_MAX);
        //x=-1+x*2;
        //y=-1+y*2;
        double distance= 1.0*x*x+1.0*y*y;
        if(distance<=1) count++;
    }
    pi=4.0*count/n;
    end = clock();
    double exe_time = ((double)(end - start)) / ( (double)(CLOCKS_PER_SEC) );
    printf("Pi: %lf\n",pi);
    printf("Time: %g seconds\n", exe_time);
    return 0;
}