162 lines
3.5 KiB
C++
162 lines
3.5 KiB
C++
/* 圖形的追蹤: 相鄰串列與廣度優先搜尋法(BFS)*/
|
||
#include <stdio.h>
|
||
#include <stdlib.h>
|
||
#define MAX_V 100 /*最大節點數*/
|
||
#define TRUE 1
|
||
#define FALSE 0
|
||
|
||
/*定義資料結構*/
|
||
typedef struct node_tag {
|
||
int vertex;
|
||
struct node_tag *link;
|
||
} Node;
|
||
|
||
/*定義佇列結構*/
|
||
typedef struct {
|
||
int items[MAX_V];
|
||
int front;
|
||
int rear;
|
||
} Queue;
|
||
|
||
Node *adjlist[MAX_V+1]; /*宣告相鄰串列*/
|
||
int visited[MAX_V+1]; /*記錄頂點是否已拜訪*/
|
||
int total_vertex;
|
||
|
||
void build_adjlist(void);
|
||
void show_adjlist(void);
|
||
void bfs(int);
|
||
Node *searchlast(Node *);
|
||
|
||
/*佇列操作函數*/
|
||
Queue* createQueue() {
|
||
Queue *q = (Queue*)malloc(sizeof(Queue));
|
||
q->front = -1;
|
||
q->rear = -1;
|
||
return q;
|
||
}
|
||
|
||
int isEmpty(Queue* q) {
|
||
return q->front == -1;
|
||
}
|
||
|
||
void enqueue(Queue* q, int value) {
|
||
if(q->front == -1)
|
||
q->front = 0;
|
||
q->rear++;
|
||
q->items[q->rear] = value;
|
||
}
|
||
|
||
int dequeue(Queue* q) {
|
||
int item = q->items[q->front];
|
||
if(q->front == q->rear) {
|
||
q->front = -1;
|
||
q->rear = -1;
|
||
} else {
|
||
q->front++;
|
||
}
|
||
return item;
|
||
}
|
||
|
||
int main()
|
||
{
|
||
build_adjlist(); /*以相鄰串列表示圖形*/
|
||
show_adjlist(); /*顯示串列之資料*/
|
||
puts("\n------Breadth First Search------");
|
||
bfs(1); /*圖形之廣度優先搜尋，以頂點1為啟始頂點*/
|
||
printf("\n");
|
||
return 0;
|
||
}
|
||
|
||
void build_adjlist()
|
||
{
|
||
FILE *fptr;
|
||
Node *node,*lastnode;
|
||
int vi,vj ,weight;
|
||
fptr = fopen("dfs_1.dat", "r");
|
||
if (fptr == NULL) {
|
||
perror("dfs.dat");
|
||
exit(0);
|
||
}
|
||
/* 讀取節點總數 */
|
||
fscanf(fptr, "%d", &total_vertex);
|
||
for (vi = 1; vi <= total_vertex; vi++) {
|
||
/*設定陣列及各串列啟始值*/
|
||
visited[vi] = FALSE;
|
||
adjlist[vi] = (Node *)malloc(sizeof(Node));
|
||
adjlist[vi]->vertex = vi;
|
||
adjlist[vi]->link = NULL;
|
||
}
|
||
/* 讀取節點資料 */
|
||
for (vi = 1; vi <= total_vertex; vi++)
|
||
for (vj = 1; vj <= total_vertex; vj++) {
|
||
fscanf(fptr,"%d",&weight);
|
||
/* 資料檔以相鄰矩陣格式儲存,以1代表相鄰
|
||
0 代表不相鄰，將相鄰頂點鏈結在各串列後 */
|
||
if (weight != 0) {
|
||
node = (Node *)malloc(sizeof(Node));
|
||
node->vertex = vj;
|
||
node->link = NULL;
|
||
lastnode = searchlast(adjlist[vi]);
|
||
lastnode->link = node;
|
||
}
|
||
}
|
||
fclose(fptr);
|
||
}
|
||
|
||
/*顯示各相鄰串列之資料*/
|
||
void show_adjlist()
|
||
{
|
||
int index;
|
||
Node *ptr;
|
||
puts("Head adjacency nodes");
|
||
puts("------------------------------");
|
||
for (index = 1; index <= total_vertex; index++) {
|
||
printf("V%-2d ",adjlist[index]->vertex);
|
||
ptr = adjlist[index]->link;
|
||
while (ptr != NULL) {
|
||
printf("--> V%d ",ptr->vertex);
|
||
ptr = ptr->link;
|
||
}
|
||
printf("\n");
|
||
}
|
||
}
|
||
|
||
/*圖形之廣度優先搜尋*/
|
||
void bfs(int start)
|
||
{
|
||
Queue* q = createQueue();
|
||
Node* ptr;
|
||
|
||
// 將起始節點加入佇列
|
||
enqueue(q, start);
|
||
visited[start] = TRUE;
|
||
|
||
while(!isEmpty(q)) {
|
||
// 從佇列取出節點並印出
|
||
int currentVertex = dequeue(q);
|
||
printf("V%d ", currentVertex);
|
||
|
||
// 將所有相鄰且未拜訪的節點加入佇列
|
||
ptr = adjlist[currentVertex]->link;
|
||
while(ptr != NULL) {
|
||
if(!visited[ptr->vertex]) {
|
||
enqueue(q, ptr->vertex);
|
||
visited[ptr->vertex] = TRUE;
|
||
}
|
||
ptr = ptr->link;
|
||
}
|
||
}
|
||
|
||
free(q);
|
||
}
|
||
|
||
/*搜尋串列最後節點函數*/
|
||
Node *searchlast(Node *linklist)
|
||
{
|
||
Node *ptr;
|
||
ptr = linklist;
|
||
while (ptr->link != NULL)
|
||
ptr = ptr->link;
|
||
return ptr;
|
||
}
|