c语言用文件操作实现有向图网的邻接矩阵存储

实现有向图网的邻接矩阵存储可以分为以下几个步骤：

1. 定义邻接矩阵的数据结构，包括节点个数、边数、邻接矩阵等。

#define MAX_VERTEX_NUM 20 // 最大节点数
typedef struct {
    int vertex[MAX_VERTEX_NUM]; // 节点数组
    int arc[MAX_VERTEX_NUM][MAX_VERTEX_NUM]; // 邻接矩阵
    int vertex_num; // 节点个数
    int arc_num; // 边数
} Graph;

2. 编写函数读取图的信息并创建邻接矩阵。这里可以采用文件操作，将图的信息存储在文件中，然后读取文件内容来创建邻接矩阵。

void create_graph(Graph* graph, char* filename) {
    FILE* fp = fopen(filename, "r");
    fscanf(fp, "%d %d", &(graph->vertex_num), &(graph->arc_num)); // 读取节点个数和边数
    for (int i = 0; i < graph->vertex_num; i++) {
        fscanf(fp, "%d", &(graph->vertex[i])); // 读取节点数组
    }
    memset(graph->arc, 0, sizeof(graph->arc)); // 初始化邻接矩阵
    int start, end, weight;
    for (int i = 0; i < graph->arc_num; i++) {
        fscanf(fp, "%d %d %d", &start, &end, &weight); // 读取边信息
        graph->arc[start][end] = weight; // 更新邻接矩阵
    }
    fclose(fp);
}

3. 编写函数输出邻接矩阵。这里可以将邻接矩阵输出到文件中，也可以直接在控制台输出。

void print_graph(Graph graph) {
    printf("Vertexes:\n");
    for (int i = 0; i < graph.vertex_num; i++) {
        printf("%d ", graph.vertex[i]);
    }
    printf("\n");
    printf("Adjacency matrix:\n");
    for (int i = 0; i < graph.vertex_num; i++) {
        for (int j = 0; j < graph.vertex_num; j++) {
            printf("%d ", graph.arc[i][j]);
        }
        printf("\n");
    }
}

完整代码如下：

#include <stdio.h>
#include <string.h>

#define MAX_VERTEX_NUM 20 // 最大节点数

typedef struct {
    int vertex[MAX_VERTEX_NUM]; // 节点数组
    int arc[MAX_VERTEX_NUM][MAX_VERTEX_NUM]; // 邻接矩阵
    int vertex_num; // 节点个数
    int arc_num; // 边数
} Graph;

void create_graph(Graph* graph, char* filename) {
    FILE* fp = fopen(filename, "r");
    fscanf(fp, "%d %d", &(graph->vertex_num), &(graph->arc_num)); // 读取节点个数和边数
    for (int i = 0; i < graph->vertex_num; i++) {
        fscanf(fp, "%d", &(graph->vertex[i])); // 读取节点数组
    }
    memset(graph->arc, 0, sizeof(graph->arc)); // 初始化邻接矩阵
    int start, end, weight;
    for (int i = 0; i < graph->arc_num; i++) {
        fscanf(fp, "%d %d %d", &start, &end, &weight); // 读取边信息
        graph->arc[start][end] = weight; // 更新邻接矩阵
    }
    fclose(fp);
}

void print_graph(Graph graph) {
    printf("Vertexes:\n");
    for (int i = 0; i < graph.vertex_num; i++) {
        printf("%d ", graph.vertex[i]);
    }
    printf("\n");
    printf("Adjacency matrix:\n");
    for (int i = 0; i < graph.vertex_num; i++) {
        for (int j = 0; j < graph.vertex_num; j++) {
            printf("%d ", graph.arc[i][j]);
        }
        printf("\n");
    }
}

int main() {
    Graph graph;
    char filename[] = "graph.txt";
    create_graph(&graph, filename);
    print_graph(graph);
    return 0;
}