c语言深度优先广度优先

深度优先搜索和广度优先搜索是两种常用的图搜索算法。在C语言中，实现深度优先搜索和广度优先搜索的方法如下：

深度优先搜索（DFS）：
使用递归或栈来实现深度优先搜索。从起点开始，沿着一条路径一直走到终点，直到无法继续为止，然后返回上一级节点，继续走其他路径，直到找到终点。

广度优先搜索（BFS）：
使用队列来实现广度优先搜索。从起点开始，将其入队，然后对队列中的每个节点，依次访问其相邻节点，并将其入队，直到找到终点。

以下是一个简单的深度优先搜索和广度优先搜索的示例代码：

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

#define MAX_SIZE 100

typedef struct Node {
    int data;
    struct Node* next;
} Node;

typedef struct Graph {
    int num_vertices;
    Node** adj_list;
    int* visited;
} Graph;

Node* create_node(int data) {
    Node* new_node = (Node*) malloc(sizeof(Node));
    new_node->data = data;
    new_node->next = NULL;
    return new_node;
}

Graph* create_graph(int num_vertices) {
    Graph* graph = (Graph*) malloc(sizeof(Graph));
    graph->num_vertices = num_vertices;
    graph->visited = (int*) malloc(num_vertices * sizeof(int));
    graph->adj_list = (Node**) malloc(num_vertices * sizeof(Node*));
    int i;
    for (i = 0; i < num_vertices; i++) {
        graph->visited[i] = 0;
        graph->adj_list[i] = NULL;
    }
    return graph;
}

void add_edge(Graph* graph, int src, int dest) {
    Node* new_node = create_node(dest);
    new_node->next = graph->adj_list[src];
    graph->adj_list[src] = new_node;
}

void dfs(Graph* graph, int vertex) {
    graph->visited[vertex] = 1;
    printf("%d ", vertex);
    Node* adj_list = graph->adj_list[vertex];
    while (adj_list != NULL) {
        int connected_vertex = adj_list->data;
        if (graph->visited[connected_vertex] == 0) {
            dfs(graph, connected_vertex);
        }
        adj_list = adj_list->next;
    }
}

void bfs(Graph* graph, int start_vertex) {
    int queue[MAX_SIZE];
    int front = -1;
    int rear = -1;
    queue[++rear] = start_vertex;
    graph->visited[start_vertex] = 1;
    while (front != rear) {
        int vertex = queue[++front];
        printf("%d ", vertex);
        Node* adj_list = graph->adj_list[vertex];
        while (adj_list != NULL) {
            int connected_vertex = adj_list->data;
            if (graph->visited[connected_vertex] == 0) {
                graph->visited[connected_vertex] = 1;
                queue[++rear] = connected_vertex;
            }
            adj_list = adj_list->next;
        }
    }
}

int main() {
    Graph* graph = create_graph(4);
    add_edge(graph, 0, 1);
    add_edge(graph, 0, 2);
    add_edge(graph, 1, 2);
    add_edge(graph, 2, 0);
    add_edge(graph, 2, 3);
    add_edge(graph, 3, 3);
    printf("DFS traversal: ");
    dfs(graph, 2);
    printf("\nBFS traversal: ");
    bfs(graph, 2);
    printf("\n");
    return 0;
}

该代码使用邻接表表示图，并实现了深度优先搜索和广度优先搜索。在主函数中，创建图并添加边，然后调用dfs()和bfs()函数，分别进行深度优先搜索和广度优先搜索。