#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
#include <sys/types.h>
#include <time.h>

#define n 1024
#define runs 500

FILE *output_ptr;
char *output_file;
char dataname[80];

int x0, x[n+1];  //initial # of As, AB array
int sum, stop;   //dynamic # of As, stop flag
double t;        //time


void init();
void update();
void file();

int main(void)
{
  int k;
  time_t t1;
  (void) time(&t1);
  srand48((long) t1);  //random seed with system time t1
  printf("This is a very good program for the Moran model...\n");
  x0=n/10;
  file();
  output_ptr = fopen(output_file,"a");
  for(k=0; k<runs; k++)
  {
    init();
    while(stop!=0) update();
    printf("%i %g\n",(sum>0 ? 1 :0),t);
    fprintf(output_ptr,"%i %g\n",(sum>0 ? 1 :0),t);
  }
  fclose(output_ptr);  
  return 0;
}


void init()
{
  int i;
  for(i=0; i<x0; i++) x[i]=1;
  for(i=x0; i<n; i++) x[i]=0;
  sum=x0;
  stop=sum*(n-sum);
  t=0;
  //  for(i=0; i<n; i++) printf("%i",x[i]);
  //  printf("  %i\n",sum);
}


void update()
{
  int i, j;
  i=lrand48()%n;
  x[n]=x[i];
  j=lrand48()%(n+1); //printf("%i ",j);
  if(x[j]!=x[n])
  {
    sum-=x[j];
    x[j]=x[n];
    sum+=x[j];
    stop=sum*(n-sum);
  }
  t+=1./n;
  //  printf("%i ",sum);
}

void file()
{
  sprintf(dataname,"moran_n%i_x0%i.dat",n,x0);
  output_file = dataname;
  output_ptr = fopen(output_file,"w");
  fclose(output_ptr);
}