有向图的DFS和BFS算法实现

/*OL_graph.c无向图的DFS和BFS遍历。 *该代码是对教科书中算法的实现 *由于水平所限，代码雍肿在所难免，欢迎批评指正，欢迎讨论切搓 * by: double; version: 0.1; date: 2009-06-13 */ #include "/usr/c/head.h"#ifndef MAX_INT#define MAX_INT 0x7fffffff#endif#ifndef MAX#define MAX 20#endiftypedef char info_type;typedef char vertex_type;typedef struct arc_type {int mark;int tailvex, headvex;struct arc_type * hlink, * tlink;info_type * info;}arc_type;typedef struct vex_type {vertex_type data;arc_type * first_in, * first_out;}vex_type;typedef struct OL_graph {vex_type vexs[MAX];int vexnum, arcnum;}OL_graph;typedef struct queue_node {int data;struct queue_node * next;}queue_node, * queue_ptr;typedef struct {queue_ptr front;queue_ptr rear;}link_queue;OL_graph G;int flag[MAX];link_queue Q;int locate_vex(OL_graph G, vertex_type v) {int i;for (i = 0; i < G.vexnum; i++)if (G.vexs[i].data == v)return i;return -1;}status init_graph(OL_graph * G) {int temp, i, p1, p2;vertex_type v1, v2;arc_type * p;printf("Input the vexnum:");if (scanf("%d", &G->vexnum) != EOF)while ((temp = getchar()) != '/n' && temp != EOF) {;}for (i = 0; i < G->vexnum; i++) {printf("No. %d:", i + 1);if (scanf("%c", &G->vexs[i].data) != EOF)while ((temp = getchar()) != '/n' && temp != EOF) {;}G->vexs[i].first_in = G->vexs[i].first_out = NULL;}printf("Input the arcnum:");if (scanf("%d", &G->arcnum) != EOF)while ((temp = getchar()) != '/n' && temp != EOF) {;}for (i = 0; i < G->arcnum; i++) {printf("No.%d v1:", i + 1);if (scanf("%c", &v1) != EOF)while ((temp = getchar()) != '/n' && temp != EOF) {;}printf("No.%d v2:", i + 1);if (scanf("%c", &v2) != EOF)while ((temp = getchar()) != '/n' && temp != EOF) {;}p1 = locate_vex(* G, v1);if (p1 == -1) {printf("v1 = %c is not exist!/n", v1);exit(ERROR);}p2 = locate_vex(* G, v2);if (p2 == -1) {printf("v2 = %c is not exist!/n", v2);exit(ERROR);}p = (arc_type *)malloc(sizeof(arc_type));if (!p) exit(OVERFLOW);p->tailvex = p1;p->headvex = p2;p->hlink = G->vexs[p2].first_in;p->tlink = G->vexs[p1].first_out;p->info = NULL;G->vexs[p2].first_in = p;G->vexs[p1].first_out = p;}return OK;}status visit(int v) {printf("%c/t", G.vexs[v].data);return OK;}int first_adj(int v) {arc_type * p;p = G.vexs[v].first_out;if (p)return p->headvex;return -1;}int next_adj(int v, int w) {arc_type * p, * q;p = G.vexs[v].first_out;while (p) {if (p->tailvex + p->headvex == v + w) {q = p->tlink;if (q)return q->headvex == w ? q->tailvex : q->headvex;}p = p->tlink;}return -1;}status DFS(int v) {int w;flag[v] = TRUE;visit(v);for (w = first_adj(v); w >= 0; w = next_adj(v, w))if (flag[w] == FALSE)DFS(w);return OK;}status DFS_graph(OL_graph G) {int i;for (i = 0; i < G.vexnum; i++)flag[i] = FALSE;for (i = 0; i < G.vexnum; i++)if (flag[i] == FALSE)DFS(i);return OK;}status init_queue(link_queue * Q) {Q->front = Q->rear = (queue_ptr)malloc(sizeof(queue_node));if (!Q->front) exit(OVERFLOW);Q->front->next = NULL;return OK;}status en_queue(link_queue * Q, int e) {queue_ptr p;p = (queue_ptr)malloc(sizeof(queue_node));if (!p) exit(OVERFLOW);p->data = e;p->next = NULL;Q->rear->next = p;Q->rear = p;return OK;}status de_queue(link_queue * Q, int * e) {queue_ptr p;if (Q->front == Q->rear) {printf("Queue empty!/n");exit(ERROR);}p = Q->front->next;* e = p->data;Q->front->next = p->next;if (p == Q->rear)Q->rear = Q->front;free(p);return OK;}int queue_empty(link_queue Q) {if (Q.front == Q.rear)return 1;return 0;}status BFS_graph(OL_graph G) {int i, e, w;init_queue(&Q);for (i = 0; i < G.vexnum; i++)flag[i] = FALSE;for (i = 0; i < G.vexnum; i++)if (flag[i] == FALSE) {flag[i] = TRUE;visit(i);en_queue(&Q, i);while (!queue_empty(Q)) {de_queue(&Q, &e);for (w = first_adj(e); w >= 0; w = next_adj(e, w))if (flag[w] == FALSE) {flag[w] = TRUE;visit(w);en_queue(&Q, w);}}}return OK;}int main(void) {init_graph(&G);printf("graph initilized OK!/n");printf("DFS result is:/n");DFS_graph(G);printf("/n");printf("BFS result is:/n");BFS_graph(G);printf("/n");return 0;}

注释见上篇算法实现