def create_basic_edgelist_files(graphs, dir_name, common_node=False):
    """Creates files with basic edge list representations of the graphs"""
    for index in range(len(graphs)):
        file = open(dir_name + '/' + 'graph' + str(index) + '.txt', 'w')
        graph = graphs[index]
        if common_node:
            num_vertices = graph.get_num_vertices()
            for i in range(num_vertices):
                file.write('0 ' + str(i + 1) + '\n')
            for edge in graph.get_edges():
                file.write(str(edge[0] + 1) + ' ' + str(edge[1] + 1) + '\n')
        else:
            for edge in graph.get_edges():
                file.write(str(edge[0]) + ' ' + str(edge[1]) + '\n')
        file.close()
