C语言拓扑排序代码怎么写

下面是一个用C语言实现拓扑排序的示例代码：

#include <stdio.h> #include <stdbool.h>  #define MAXVERTICES 100  struct Graph {     int vertices;     int edges;     int adjacencyMatrix[MAXVERTICES][MAXVERTICES]; };  void initializeGraph(struct Graph* graph, int vertices) {     graph->vertices = vertices;     graph->edges = 0;      for (int i = 0; i < vertices; i++) {         for (int j = 0; j < vertices; j++) {             graph->adjacencyMatrix[i][j] = 0;         }     } }  void addEdge(struct Graph* graph, int startVertex, int endVertex) {     graph->adjacencyMatrix[startVertex][endVertex] = 1;     graph->edges++; }  void topologicalSortUtil(struct Graph* graph, int vertex, bool visited[], int stack[], int* stackIndex) {     visited[vertex] = true;      for (int i = 0; i < graph->vertices; i++) {         if (graph->adjacencyMatrix[vertex][i] == 1 && !visited[i]) {             topologicalSortUtil(graph, i, visited, stack, stackIndex);         }     }      stack[(*stackIndex)++] = vertex; }  void topologicalSort(struct Graph* graph) {     bool visited[MAXVERTICES] = {false};     int stack[MAXVERTICES];     int stackIndex = 0;      for (int i = 0; i < graph->vertices; i++) {         if (!visited[i]) {             topologicalSortUtil(graph, i, visited, stack, &stackIndex);         }     }      printf("Topological Sort: ");      while (stackIndex > 0) {         printf("%d ", stack[--stackIndex]);     }      printf("\n"); }  int main() {     struct Graph graph;     int vertices, edges, startVertex, endVertex;      printf("Enter the number of vertices in the graph: ");     scanf("%d", &vertices);      initializeGraph(&graph, vertices);      printf("Enter the number of edges in the graph: ");     scanf("%d", &edges);      for (int i = 0; i < edges; i++) {         printf("Enter the start and end vertex of edge %d: ", i + 1);         scanf("%d %d", &startVertex, &endVertex);         addEdge(&graph, startVertex, endVertex);     }      topologicalSort(&graph);      return 0; } 

这个代码中，首先定义了一个结构体Graph来表示图，其中vertices表示顶点的个数，edges表示边的个数，adjacencyMatrix表示邻接矩阵。

然后定义了几个函数来操作图，包括initializeGraph用于初始化图，addEdge用于添加边，topologicalSortUtil用于递归实现拓扑排序，topologicalSort用于调用topologicalSortUtil进行拓扑排序。

在main函数中，首先获取用户输入的顶点个数和边的个数，然后通过addEdge函数添加边，最后调用topologicalSort函数进行拓扑排序。

注意：该示例代码中使用邻接矩阵来表示图，适用于边数较少的情况。如果边数较多，推荐使用邻接表来表示图。