Merge pull request wangzheng0822#178 from RichardWeiYang/master

implement Graph in c

c-cpp/30_Graph/graph.c

@@ -0,0 +1,138 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <time.h>
+
+struct vertex;
+struct vertex_adjs {
+	struct vertex *v;
+	struct vertex_adjs *next;
+};
+
+struct vertex {
+	int data;
+	struct vertex_adjs *adj;
+};
+
+#define MAX_GRAPH_VERTEX (1 << 8)
+struct graph {
+	struct vertex *vxs[MAX_GRAPH_VERTEX];
+};
+
+void init_graph(struct graph *graph)
+{
+	int i;
+
+	for (i = 0; i < MAX_GRAPH_VERTEX; i++)
+		graph->vxs[i] = NULL;
+}
+
+struct vertex *create_vertex(int data)
+{
+	struct vertex *v;
+
+	v = malloc(sizeof(struct vertex));
+
+	if (v) {
+		v->data = data;
+		v->adj = NULL;
+	}
+
+	return v;
+}
+
+struct vertex_adjs *create_vertex_adj(struct vertex *v)
+{
+	struct vertex_adjs *v_adj;
+
+	v_adj = malloc(sizeof(struct vertex_adjs));
+
+	if (!v_adj)
+		return NULL;
+
+	v_adj->v = v;
+	v_adj->next = NULL;
+	return v_adj;
+}
+
+void insert_adj(struct vertex *v, struct vertex *adj)
+{
+	struct vertex_adjs **v_adj;
+
+	v_adj = &v->adj;
+
+	while (*v_adj)
+		v_adj = &(*v_adj)->next;
+
+	*v_adj = create_vertex_adj(adj);
+}
+
+void dump_raw(struct graph *graph)
+{
+	int i;
+
+	for (i = 0; i < MAX_GRAPH_VERTEX; i++) {
+		struct vertex *v = graph->vxs[i];
+		struct vertex_adjs *adj;
+		if (v == NULL)
+			continue;
+
+		printf("Vertex[%02d]: %8d ->", i, v->data);
+
+		adj = v->adj;
+		while (adj) {
+			printf(" %8d,", adj->v->data);
+			adj = adj->next;
+		}
+		printf("\n");
+	}
+}
+
+/* 
+  1 ----- 2 ----- 3
+  |     / |     /
+  |    /  |    / 
+  |   /   |   /  
+  |  /    |  /   
+  | /     | /    
+  4 ----- 5
+*/
+void fake_a_graph(struct graph *graph)
+{
+	int i;
+
+	init_graph(graph);
+
+	for (i = 0; i < 5; i++)
+		graph->vxs[i] = create_vertex(i+1);
+
+	/* connect 1 -> 2, 1 -> 4 */
+	insert_adj(graph->vxs[0], graph->vxs[1]);
+	insert_adj(graph->vxs[0], graph->vxs[3]);
+	/* connect 2 -> 1, 2 -> 3, 2 -> 5, 2 -> 4 */
+	insert_adj(graph->vxs[1], graph->vxs[0]);
+	insert_adj(graph->vxs[1], graph->vxs[2]);
+	insert_adj(graph->vxs[1], graph->vxs[4]);
+	insert_adj(graph->vxs[1], graph->vxs[3]);
+	/* connect 3 -> 2, 3 -> 5 */
+	insert_adj(graph->vxs[2], graph->vxs[1]);
+	insert_adj(graph->vxs[2], graph->vxs[4]);
+	/* connect 4 -> 1, 4 -> 2, 4 -> 5 */
+	insert_adj(graph->vxs[3], graph->vxs[0]);
+	insert_adj(graph->vxs[3], graph->vxs[1]);
+	insert_adj(graph->vxs[3], graph->vxs[4]);
+	/* connect 5 -> 4, 5 -> 2, 5 -> 3 */
+	insert_adj(graph->vxs[4], graph->vxs[3]);
+	insert_adj(graph->vxs[4], graph->vxs[1]);
+	insert_adj(graph->vxs[4], graph->vxs[3]);
+}
+
+int main()
+{
+	struct graph g;
+
+	fake_a_graph(&g);
+	dump_raw(&g);
+	return 0;
+}