C语言带权无向图的邻接表创建和输出

创建带权无向图的邻接表，可以按照以下步骤实现：

1. 定义结构体存储节点信息和边权值

typedef struct EdgeNode {
    int adjvex;     // 相邻节点编号
    int weight;     // 边权值
    struct EdgeNode *next;  // 指向下一个邻接节点的指针
}EdgeNode;

typedef struct VertexNode {
    int vertex;  // 当前节点编号
    EdgeNode *firstedge;  // 指向第一个邻接节点的指针
}VertexNode;

typedef struct Graph {
    VertexNode adjlist[MAXSIZE];  // 邻接表
    int num_vertexes;   // 节点数目
    int num_edges;      // 边数目
}Graph;

2. 初始化邻接表

void initGraph(Graph *G, int n, int m) {
    G->num_vertexes = n;
    G->num_edges = m;
    for (int i = 0; i < n; i++) {
        G->adjlist[i].vertex = i;
        G->adjlist[i].firstedge = NULL;
    }
}

3. 添加边

void addEdge(Graph *G, int u, int v, int w) {
    EdgeNode *p = (EdgeNode*)malloc(sizeof(EdgeNode));
    p->adjvex = v;
    p->weight = w;
    p->next = G->adjlist[u].firstedge;
    G->adjlist[u].firstedge = p;

    p = (EdgeNode*)malloc(sizeof(EdgeNode));
    p->adjvex = u;
    p->weight = w;
    p->next = G->adjlist[v].firstedge;
    G->adjlist[v].firstedge = p;
}

4. 输出邻接表

void printGraph(Graph *G) {
    for (int i = 0; i < G->num_vertexes; i++) {
        printf("Vertex %d: ", i);
        EdgeNode *p = G->adjlist[i].firstedge;
        while (p) {
            printf("(%d, %d) ", p->adjvex, p->weight);
            p = p->next;
        }
        printf("\n");
    }
}

完整代码示例：

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

#define MAXSIZE 100

typedef struct EdgeNode {
    int adjvex;
    int weight;
    struct EdgeNode *next;
}EdgeNode;

typedef struct VertexNode {
    int vertex;
    EdgeNode *firstedge;
}VertexNode;

typedef struct Graph {
    VertexNode adjlist[MAXSIZE];
    int num_vertexes;
    int num_edges;
}Graph;

void initGraph(Graph *G, int n, int m) {
    G->num_vertexes = n;
    G->num_edges = m;
    for (int i = 0; i < n; i++) {
        G->adjlist[i].vertex = i;
        G->adjlist[i].firstedge = NULL;
    }
}

void addEdge(Graph *G, int u, int v, int w) {
    EdgeNode *p = (EdgeNode*)malloc(sizeof(EdgeNode));
    p->adjvex = v;
    p->weight = w;
    p->next = G->adjlist[u].firstedge;
    G->adjlist[u].firstedge = p;

    p = (EdgeNode*)malloc(sizeof(EdgeNode));
    p->adjvex = u;
    p->weight = w;
    p->next = G->adjlist[v].firstedge;
    G->adjlist[v].firstedge = p;
}

void printGraph(Graph *G) {
    for (int i = 0; i < G->num_vertexes; i++) {
        printf("Vertex %d: ", i);
        EdgeNode *p = G->adjlist[i].firstedge;
        while (p) {
            printf("(%d, %d) ", p->adjvex, p->weight);
            p = p->next;
        }
        printf("\n");
    }
}

int main() {
    Graph G;
    int n = 5, m = 6;
    initGraph(&G, n, m);
    addEdge(&G, 0, 1, 1);
    addEdge(&G, 0, 2, 2);
    addEdge(&G, 1, 2, 3);
    addEdge(&G, 1, 3, 4);
    addEdge(&G, 2, 3, 5);
    addEdge(&G, 3, 4, 6);
    printGraph(&G);
    return 0;
}