无向图的DFS和BFS算法实现

/*AML_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 ((int)(~0U>>1)) #endif #ifndef MAX #define MAX 20 #endif typedef 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; }