用 C 语言程序邻接表表示节点的出度值 0 -> 2 -> 1 1 2 -> 3 3 -> 0

这是一个有向图，可以用邻接表来表示。邻接表是一个数组，其中每个元素都指向一个链表，链表中存储该节点指向的所有节点。

下面是用 C 语言程序实现该图的邻接表表示方法，其中定义了一个结构体来表示链表中的节点，节点中存储了指向的节点的编号和下一个节点的指针：

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

// 链表节点结构体
typedef struct Node {
    int dest;
    struct Node* next;
} Node;

// 邻接表结构体
typedef struct Graph {
    int numVertices;
    Node** adjLists;
} Graph;

// 创建新节点
Node* createNode(int dest) {
    Node* newNode = (Node*) malloc(sizeof(Node));
    newNode->dest = dest;
    newNode->next = NULL;
    return newNode;
}

// 创建邻接表
Graph* createGraph(int numVertices) {
    Graph* graph = (Graph*) malloc(sizeof(Graph));
    graph->numVertices = numVertices;
    graph->adjLists = (Node**) malloc(numVertices * sizeof(Node*));
    int i;
    for (i = 0; i < numVertices; i++) {
        graph->adjLists[i] = NULL;
    }
    return graph;
}

// 添加边
void addEdge(Graph* graph, int src, int dest) {
    Node* newNode = createNode(dest);
    newNode->next = graph->adjLists[src];
    graph->adjLists[src] = newNode;
}

// 输出每个节点的出度
void printOutDegree(Graph* graph) {
    int i;
    for (i = 0; i < graph->numVertices; i++) {
        int outDegree = 0;
        Node* temp = graph->adjLists[i];
        while (temp != NULL) {
            outDegree++;
            temp = temp->next;
        }
        printf("Node %d has out degree %d\n", i, outDegree);
    }
}

int main() {
    Graph* graph = createGraph(4);
    addEdge(graph, 0, 2);
    addEdge(graph, 2, 1);
    addEdge(graph, 2, 3);
    addEdge(graph, 3, 0);
    printOutDegree(graph);
    return 0;
}

输出结果为：

Node 0 has out degree 1
Node 1 has out degree 0
Node 2 has out degree 2
Node 3 has out degree 1

可以看到，节点0的出度为1，节点1的出度为0，节点2的出度为2，节点3的出度为1。