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

struct node {
	int vertex;
	struct node* next;
};

struct node* createNode(int);

struct Graph {
	int numVertices;
	struct node** adjLists;
};

struct Graph* createGraph(int vertices);
void addEdge(struct Graph* graph, int src, int dest);
void printGraph(struct Graph* graph);

int main() {
	struct Graph* graph = createGraph(6);
	addEdge(graph, 0, 1);
	addEdge(graph, 0, 2);
	printGraph(graph);
	return 0;
}

struct node* createNode(int v) {
	struct node* newNode = malloc(sizeof(struct node));
	newNode->vertex = v;
	newNode->next = NULL;
	return newNode;
}

struct Graph* createGraph(int vertices) {
	struct Graph* graph = malloc(sizeof(struct Graph));
	graph->numVertices = vertices;
	graph->adjLists = malloc(vertices * sizeof(struct node*));

	int i;
	for (i=0; i<vertices; i++) graph->adjLists[i] = NULL;
}

void addEdge(struct Graph* graph, int src, int dest) {
	struct node* newNode = createNode(dst);
	newNode->next = graph->adjLists[src];
	graph->adjLists[src] = newNode;

	newNode = createNode(src);
	newNode->next = graph->adjLists[dest];
	graph->adjLists[dest] = newNode;
}

void printGraph(struct Graph* graph) {
	int v;
	for (v=0; v<graph->numVertices; v++) {
		struct node* temp = graph->adjLists[v];
		printf("\nAdjacency list of vertex %d\n", v);
		while (temp) {
			printf("%d -> ", temp->vertex);
			temp = temp->next;
		}
		printf("\n");
	}
}