1#include <stdbool.h>
 2
 3typedef struct {
 4  char label;
 5} Vertex;
 6
 7typedef struct {
 8  Vertex *vertices[128];
 9  bool edges[128][128];
10} Graph;
11
12Graph *graph_initialize(void);
13Vertex *graph_add_vertex(Graph *graph, char label);
14void graph_add_edge(Graph *graph, Vertex *a, Vertex *b);
15bool graph_has_edge(Graph *graph, Vertex *a, Vertex *b);