#include <igraph.h>
#include <stdio.h>
int print_vector(const igraph_vector_t *v) 
{
  long int i, n=igraph_vector_size(v);
  for (i=0; i<n; i++) 
  {
    printf("%.2g", (double)VECTOR(*v)[i]);
    if (i!=n-1) { printf(" "); }
  }
  printf("\n");
  return 0;
}

int print_matrix(const igraph_matrix_t *m) 
{
  long int i, j, nrow=igraph_matrix_nrow(m), ncol=igraph_matrix_ncol(m);
  for (i=0; i<nrow; i++) 
  {
    for (j=0; j<ncol; j++) 
    {
      printf("%.2g", (double)MATRIX(*m, i, j));
      if (j!=ncol-1) { printf(" "); }
    }
    printf("\n");
  }
  return 0;
}

int main(int argc, char *argv[]) 
{

  igraph_t g;
  igraph_matrix_t merges;
  igraph_vector_t membership;
  long int i, j;
  igraph_arpack_options_t options;
  FILE *fp;
   
  fp=fopen(argv[1],"r");

  printf("\n");

  if(argc!= 2)
  {
    puts("Improper number of arguments" ) ;
    return 0;
  }

  igraph_read_graph_edgelist(&g,fp,0,0);
  fclose(fp);
  //igraph_simplify(&g,1,0);
  
  igraph_matrix_init(&merges, 0, 0);
  igraph_vector_init(&membership, 0);
  igraph_arpack_options_init(&options);

  igraph_community_leading_eigenvector(&g, &merges, &membership,2,
				       &options);
  printf("\n\n");
  print_matrix(&merges);
  printf("\n");
  print_vector(&membership);
  printf("\n\n");

  igraph_vector_destroy(&membership);
  igraph_matrix_destroy(&merges);
  igraph_destroy(&g);
  printf("\n");
  return 0;
}