C 语言代码示例

以下是一个较为复杂的 C 语言代码示例，它演示了如何使用链表数据结构实现一个简单的图（Graph）数据结构，并实现图的深度优先搜索（DFS）算法：

#include <stdio.h>
#include <stdlib.h>

struct Node {
    int vertex;
    struct Node* next;
};

struct Graph {
    int numVertices;
    struct Node** adjacencyList;
};

struct Node* createNode(int v) {
    struct Node* newNode = malloc(sizeof(struct Node));
    newNode->vertex = v;
    newNode->next = NULL;
    return newNode;
}

struct Graph* createGraph(int vertices) {
    struct Graph* graph = malloc(sizeof(struct Graph));
    graph->numVertices = vertices;
    graph->adjacencyList = malloc(vertices * sizeof(struct Node*));
    
    for (int i = 0; i < vertices; i++) {
        graph->adjacencyList[i] = NULL;
    }
    
    return graph;
}

void addEdge(struct Graph* graph, int src, int dest) {
    struct Node* newNode = createNode(dest);
    newNode->next = graph->adjacencyList[src];
    graph->adjacencyList[src] = newNode;
    
    newNode = createNode(src);
    newNode->next = graph->adjacencyList[dest];
    graph->adjacencyList[dest] = newNode;
}

void DFS(struct Graph* graph, int vertex, int* visited) {
    visited[vertex] = 1;
    printf("%d ", vertex);
    
    struct Node* adjList = graph->adjacencyList[vertex];
    while (adjList != NULL) {
        int connectedVertex = adjList->vertex;
        if (visited[connectedVertex] == 0) {
            DFS(graph, connectedVertex, visited);
        }
        adjList = adjList->next;
    }
}

int main() {
    int numVertices = 6;
    struct Graph* graph = createGraph(numVertices);
    
    addEdge(graph, 0, 1);
    addEdge(graph, 0, 2);
    addEdge(graph, 1, 3);
    addEdge(graph, 2, 4);
    addEdge(graph, 3, 4);
    addEdge(graph, 3, 5);
    
    int visited[numVertices];
    for (int i = 0; i < numVertices; i++) {
        visited[i] = 0;
    }
    
    printf("深度优先搜索结果：");
    DFS(graph, 0, visited);

    return 0;
}

上述代码实现了一个使用链表数据结构表示的简单无向图（undirected graph）数据结构，并展示了如何实现图的深度优先搜索（DFS）算法。在 main 函数中，我们创建了一个包含 6 个顶点的图，并添加了边连接这些顶点。然后，我们使用深度优先搜索来遍历这个图，并打印出遍历的结果。

请注意，这个例子对于初学者可能具有一定的复杂度，涉及到动态内存分配和链表数据结构的操作。实际编程中，根据需求选择适当的数据结构和算法是非常重要的。