#include <igraph.h>
#include <stdio.h>


int main(void)
{
     FILE *fp;   
     	
     fp = fopen("karate.txt", "r"); 

 
    
     igraph_t graph;
     igraph_real_t modularity;
     igraph_read_graph_edgelist(&graph, fp, 0, 0);
     igraph_matrix_t merges;
     igraph_vector_t result;
     igraph_vector_t membership;
     igraph_vector_init( &result, 0);
     igraph_vector_init( &membership, 0);
     igraph_matrix_init( &merges, 0,0);
     int nodes;
     nodes = 34;
     
      int i;     
 
      //    igraph_community_edge_betweenness(&graph, &result, NULL,  &merges, NULL, 0);    // <--- to do eb comm. detection
	igraph_community_fastgreedy(&graph, NULL, &merges, NULL);   

        for (i=1 ;i< nodes;i++)  {	
        	igraph_community_to_membership(&merges,  nodes,  i, &membership, NULL);     // <-- should construct community vector
        	igraph_modularity(&graph ,&membership, &modularity, NULL);            // <-- and find modularity
	 	printf( "%f\n", modularity )   ;                      
	   }


     igraph_destroy(&graph);
     return 0;
}