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https://github.com/krahets/hello-algo.git
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Reimplement the graph code for C
This commit is contained in:
krahets
@@ -6,259 +6,166 @@
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#include "../utils/common.h"
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typedef struct Vertex Vertex;
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typedef struct Node Node;
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typedef struct LinkedList LinkedList;
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// 假设节点最大数量为 100
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#define MAX_SIZE 100
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void freeVertex(Vertex *);
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void freeLinklist(LinkedList *);
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LinkedList *newLinklist(Vertex *);
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/* 节点结构体 */
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typedef struct AdjListNode {
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Vertex *vertex; // 顶点
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struct AdjListNode *next; // 后继节点
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} AdjListNode;
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/* 链表节点 */
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struct Node {
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// 链表节点内包含顶点类和下一个节点地址
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Vertex *val;
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Node *next;
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};
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/* 链表节点构造函数 */
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Node *newNode() {
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Node *n = (Node *)malloc(sizeof(Node));
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n->next = 0;
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n->val = 0;
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return n;
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}
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/* 顶点节点类 */
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struct Vertex {
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// 节点值
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int val;
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// 与其它节点相连接的边的链表
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LinkedList *list;
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// 索引位，标记该顶点在顶点列表中的索引
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unsigned int pos;
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};
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/* 顶点节点构造函数 */
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Vertex *newVertex(int val) {
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Vertex *vet = (Vertex *)malloc(sizeof(Vertex));
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// 为新节点赋值并建立该节点的链表
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vet->val = val;
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vet->list = newLinklist(vet);
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return vet;
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}
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/* 顶点内存释放函数 */
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void freeVertex(Vertex *val) {
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// 释放该顶点和该顶点的链表的内存
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freeLinklist(val->list);
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free(val);
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}
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/* 链表 */
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struct LinkedList {
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Node *head;
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Node *tail;
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};
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/* 链表头插法 */
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void pushFront(LinkedList *list, Vertex *val) {
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Node *temp = newNode();
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temp->val = val;
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temp->next = list->head->next;
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list->head->next = temp;
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if (list->tail == list->head) {
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list->tail = temp;
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}
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}
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/* 链表尾插法 */
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void pushBack(LinkedList *list, Vertex *val) {
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Node *temp = newNode();
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temp->val = val;
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temp->next = 0;
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list->tail->next = temp;
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list->tail = temp;
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}
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/* 根据顶点地址与该顶点连接的删除边 */
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void removeLink(LinkedList *list, Vertex *val) {
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Node *temp = list->head->next;
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Node *front = list->head;
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while (temp != 0) {
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if (temp->val == val) {
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front->next = temp->next;
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if (list->tail == temp) {
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list->tail = front;
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}
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free(temp);
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return;
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}
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front = temp;
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temp = temp->next;
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}
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if (temp->next == 0) {
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printf("vertex not found!\n");
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}
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}
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/* 根据顶点地址删除顶点 */
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void removeItem(LinkedList *list, Vertex *val) {
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Node *temp = list->head->next;
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Node *front = list->head;
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while (temp != 0) {
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if (temp->val == val) {
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front->next = temp->next;
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if (list->tail == temp) {
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list->tail = front;
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}
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freeVertex(val);
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free(temp);
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return;
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}
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front = temp;
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temp = temp->next;
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}
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if (temp->next == 0) {
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printf("vertex not found!\n");
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}
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}
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/* 释放链表内存 */
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void freeLinklist(LinkedList *list) {
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Node *temp = list->head->next;
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while (temp != 0) {
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free(list->head);
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list->head = temp;
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temp = temp->next;
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}
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free(list->head);
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list->head = 0;
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free(list);
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}
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/* 链表构造函数 */
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LinkedList *newLinklist(Vertex *val) {
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LinkedList *newLinklist = (LinkedList *)malloc(sizeof(LinkedList));
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newLinklist->head = newNode();
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newLinklist->head->val = val;
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newLinklist->tail = newLinklist->head;
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newLinklist->head->next = 0;
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return newLinklist;
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}
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/* 基于邻接链表实现的无向图类结构 */
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/* 基于邻接表实现的无向图类 */
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typedef struct {
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Vertex **vertices; // 邻接表
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unsigned int size; // 顶点数量
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unsigned int capacity; // 顶点容量
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AdjListNode *heads[MAX_SIZE]; // 节点数组
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int size; // 节点数量
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} GraphAdjList;
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/* 添加边 */
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void addEdge(GraphAdjList *graph, int i, int j) {
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// 越界检查
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if (i < 0 || j < 0 || i == j || i >= graph->size || j >= graph->size) {
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printf("Out of range in %s:%d\n", __FILE__, __LINE__);
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return;
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/* 构造函数 */
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GraphAdjList *newGraphAdjList() {
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GraphAdjList *graph = (GraphAdjList *)malloc(sizeof(GraphAdjList));
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if (!graph) {
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return NULL;
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}
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// 查找欲添加边的顶点 vet1 - vet2
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Vertex *vet1 = graph->vertices[i];
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Vertex *vet2 = graph->vertices[j];
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// 连接顶点 vet1 - vet2
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pushBack(vet1->list, vet2);
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pushBack(vet2->list, vet1);
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graph->size = 0;
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for (int i = 0; i < MAX_SIZE; i++) {
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graph->heads[i] = NULL;
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}
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return graph;
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}
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/* 析构函数 */
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void delGraphAdjList(GraphAdjList *graph) {
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for (int i = 0; i < graph->size; i++) {
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AdjListNode *cur = graph->heads[i];
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while (cur != NULL) {
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AdjListNode *next = cur->next;
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if (cur != graph->heads[i]) {
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free(cur);
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}
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cur = next;
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}
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free(graph->heads[i]->vertex);
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free(graph->heads[i]);
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}
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free(graph);
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}
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/* 查找顶点对应的节点 */
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AdjListNode *findNode(GraphAdjList *graph, Vertex *vet) {
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for (int i = 0; i < graph->size; i++) {
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if (graph->heads[i]->vertex == vet) {
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return graph->heads[i];
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}
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}
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return NULL;
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}
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/* 添加边辅助函数 */
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void addEdgeHelper(AdjListNode *head, Vertex *vet) {
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AdjListNode *node = (AdjListNode *)malloc(sizeof(AdjListNode));
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node->vertex = vet;
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// 头插法
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node->next = head->next;
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head->next = node;
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}
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/* 添加边 */
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void addEdge(GraphAdjList *graph, Vertex *vet1, Vertex *vet2) {
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AdjListNode *head1 = findNode(graph, vet1);
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AdjListNode *head2 = findNode(graph, vet2);
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assert(head1 != NULL && head2 != NULL && head1 != head2);
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// 添加边 vet1 - vet2
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addEdgeHelper(head1, vet2);
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addEdgeHelper(head2, vet1);
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}
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/* 删除边辅助函数 */
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void removeEdgeHelper(AdjListNode *head, Vertex *vet) {
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AdjListNode *pre = head;
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AdjListNode *cur = head->next;
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// 在链表中搜索 vet 对应节点
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while (cur != NULL && cur->vertex != vet) {
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pre = cur;
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cur = cur->next;
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}
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if (cur == NULL)
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return;
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// 将 vet 对应节点从链表中删除
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pre->next = cur->next;
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// 释放内存
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free(cur);
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}
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/* 删除边 */
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void removeEdge(GraphAdjList *graph, int i, int j) {
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// 越界检查
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if (i < 0 || j < 0 || i == j || i >= graph->size || j >= graph->size) {
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printf("Out of range in %s:%d\n", __FILE__, __LINE__);
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return;
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}
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// 查找欲删除边的顶点 vet1 - vet2
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Vertex *vet1 = graph->vertices[i];
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Vertex *vet2 = graph->vertices[j];
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// 移除待删除边 vet1 - vet2
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removeLink(vet1->list, vet2);
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removeLink(vet2->list, vet1);
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void removeEdge(GraphAdjList *graph, Vertex *vet1, Vertex *vet2) {
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AdjListNode *head1 = findNode(graph, vet1);
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AdjListNode *head2 = findNode(graph, vet2);
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assert(head1 != NULL && head2 != NULL);
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// 删除边 vet1 - vet2
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removeEdgeHelper(head1, head2->vertex);
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removeEdgeHelper(head2, head1->vertex);
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}
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/* 添加顶点 */
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void addVertex(GraphAdjList *graph, int val) {
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// 若大小超过容量，则扩容
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if (graph->size >= graph->capacity) {
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Vertex **tempList = (Vertex **)malloc(sizeof(Vertex *) * 2 * graph->capacity);
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memcpy(tempList, graph->vertices, sizeof(Vertex *) * graph->size);
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free(graph->vertices); // 释放原邻接表内存
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graph->vertices = tempList; // 指向新邻接表
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graph->capacity = graph->capacity * 2; // 容量扩大至2倍
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}
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// 申请新顶点内存并将新顶点地址存入顶点列表
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Vertex *newV = newVertex(val); // 建立新顶点
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newV->pos = graph->size; // 为新顶点标记下标
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newV->list = newLinklist(newV); // 为新顶点建立链表
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graph->vertices[graph->size] = newV; // 将新顶点加入邻接表
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graph->size++;
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void addVertex(GraphAdjList *graph, Vertex *vet) {
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assert(graph != NULL && graph->size < MAX_SIZE);
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AdjListNode *head = (AdjListNode *)malloc(sizeof(AdjListNode));
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head->vertex = vet;
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head->next = NULL;
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// 在邻接表中添加一个新链表
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graph->heads[graph->size++] = head;
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}
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/* 删除顶点 */
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void removeVertex(GraphAdjList *graph, unsigned int index) {
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// 越界检查
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if (index < 0 || index >= graph->size) {
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printf("Out of range in %s:%d\n", __FILE__, __LINE__);
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exit(1);
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void removeVertex(GraphAdjList *graph, Vertex *vet) {
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AdjListNode *node = findNode(graph, vet);
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assert(node != NULL);
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// 在邻接表中删除顶点 vet 对应的链表
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AdjListNode *cur = node, *pre = NULL;
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while (cur) {
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pre = cur;
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cur = cur->next;
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free(pre);
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}
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Vertex *vet = graph->vertices[index]; // 查找待删节点
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if (vet == 0) { // 若不存在该节点，则返回
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printf("index is:%d\n", index);
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printf("Out of range in %s:%d\n", __FILE__, __LINE__);
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return;
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// 遍历其他顶点的链表，删除所有包含 vet 的边
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for (int i = 0; i < graph->size; i++) {
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cur = graph->heads[i];
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pre = NULL;
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while (cur) {
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pre = cur;
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cur = cur->next;
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if (cur && cur->vertex == vet) {
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pre->next = cur->next;
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free(cur);
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break;
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}
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}
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}
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// 遍历待删除顶点的链表，将所有与待删除节点有关的边删除
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Node *temp = vet->list->head->next;
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while (temp != 0) {
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removeLink(temp->val->list, vet); // 删除与该顶点有关的边
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temp = temp->next;
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// 将该顶点之后的顶点向前移动，以填补空缺
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int i;
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for (i = 0; i < graph->size; i++) {
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if (graph->heads[i] == node)
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break;
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}
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// 将顶点前移
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for (int i = index; i < graph->size - 1; i++) {
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graph->vertices[i] = graph->vertices[i + 1]; // 顶点前移
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graph->vertices[i]->pos--; // 所有前移的顶点索引值减 1
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for (int j = i; j < graph->size - 1; j++) {
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graph->heads[j] = graph->heads[j + 1];
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}
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graph->vertices[graph->size - 1] = 0;
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graph->size--;
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// 释放内存
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freeVertex(vet);
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free(vet);
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}
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/* 打印顶点与邻接矩阵 */
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void printGraph(GraphAdjList *graph) {
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printf("邻接表 =\n");
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for (int i = 0; i < graph->size; i++) {
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Node *n = graph->vertices[i]->list->head->next;
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printf("%d: [", graph->vertices[i]->val);
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while (n != 0) {
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if (n->next != 0) {
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printf("%d, ", n->val->val);
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} else {
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printf("%d", n->val->val);
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}
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n = n->next;
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/* 打印邻接表 */
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void printGraph(const GraphAdjList *graph) {
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printf("邻接表 =\n");
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for (int i = 0; i < graph->size; ++i) {
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AdjListNode *node = graph->heads[i];
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printf("%d: [", node->vertex->val);
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node = node->next;
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while (node) {
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printf("%d, ", node->vertex->val);
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node = node->next;
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}
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printf("]\n");
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}
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}
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/* 构造函数 */
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GraphAdjList *newGraphAdjList(unsigned int verticesCapacity) {
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// 申请内存
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GraphAdjList *newGraph = (GraphAdjList *)malloc(sizeof(GraphAdjList));
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// 建立顶点表并分配内存
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newGraph->vertices = (Vertex **)malloc(sizeof(Vertex *) * verticesCapacity); // 为顶点列表分配内存
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memset(newGraph->vertices, 0, sizeof(Vertex *) * verticesCapacity); // 顶点列表置 0
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newGraph->size = 0; // 初始化顶点数量
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newGraph->capacity = verticesCapacity; // 初始化顶点容量
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// 返回图指针
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return newGraph;
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}
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