#include<stdlib.h>
#include<stdio.h>

struct digraph //Estrutura do grafo, V e A são contadores, matrix_adj é um ponteiro para um array de ponteiros
{
    int V , A;
    int **matrix_adj;
};

typedef struct digraph* Digraph;
int **matrix_alloc(int r,int c,int val);
Digraph graph_alloc(int vertex);
void insert(Digraph G, int v, int w);
void show(Digraph G);

int main(void)
{
    Digraph G;
    G = graph_alloc(6);
    insert(G, 1,2);
    insert(G, 1,3);
    insert(G, 2,4);
    insert(G, 3,4);
    insert(G, 4,5);
    insert(G, 5,6);
    show(G);
    return 0;

}

int **matrix_alloc(int r,int c,int val)
{
    int i, j;
    int **matrix = (int**)malloc(r*sizeof(int*));// aloca linhas
    for(i=0;i<r;i++)
    {
        matrix[i] = (int*)malloc(c*sizeof(int));//aloca colunas
        for(j=0;j<c;j++)
        {
            matrix[i][j] = val;
        }
    }
    return matrix;
}

Digraph graph_alloc(int vertex)
{
    Digraph G = malloc(sizeof(struct digraph));
    G->V = vertex;
    G->A = 0;
    G->matrix_adj = matrix_alloc(vertex, vertex, 0);
    return G;
}

void insert(Digraph G,int v, int w)
{
    if(G->matrix_adj[v][w] == 0)
    {
        G->matrix_adj[v][w] = 1;
        G->matrix_adj[w][v] = 1;
        G->A++;
    }
}

void show(Digraph G)
{
    int v, w;
    for(v=0; v<G->V; v++)
    {
        for(w=0; w<G->V;w++)
        {
            printf("%d ", G->matrix_adj[v][w]);
        }
        printf("\n");
    }
    printf("\n");
    printf("Vertices: ", G->V);
    printf("Arestas:  ", G->A);
}