写一个C语言代码，同时使用 MPI+ OpenMP 完成一个并行的广度优先搜索图算法以读文件输入，输出遍历结果和运行时间

好的，以下是一个使用MPI+OpenMP并行化广度优先搜索的C语言代码，可以读取文件输入，输出遍历结果和运行时间。请注意，此代码仅供参考，您可能需要根据自己的环境和需求进行修改。

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <mpi.h>
#include <omp.h>

#define MAX_LINE_LEN 100
#define ROOT 0

int main(int argc, char* argv[]) {
    int size, rank;
    MPI_Init(&argc, &argv);
    MPI_Comm_size(MPI_COMM_WORLD, &size);
    MPI_Comm_rank(MPI_COMM_WORLD, &rank);

    double start_time = MPI_Wtime();

    // 读取输入文件
    char* filename = argv[1];
    FILE* fp = fopen(filename, "r");
    if (fp == NULL) {
        printf("Error: Unable to open input file %s!\n", filename);
        MPI_Finalize();
        return 1;
    }

    // 解析输入文件，构建邻接列表
    int nodes, edges;
    fscanf(fp, "%d %d", &nodes, &edges);
    int* adj_lists[nodes];
    int adj_list_sizes[nodes];
    memset(adj_list_sizes, 0, sizeof(adj_list_sizes));
    for (int i = 0; i < edges; i++) {
        int src, dest;
        fscanf(fp, "%d %d", &src, &dest);
        adj_list_sizes[src]++;
        adj_list_sizes[dest]++;
    }
    for (int i = 0; i < nodes; i++) {
        adj_lists[i] = malloc(adj_list_sizes[i] * sizeof(int));
        adj_list_sizes[i] = 0;
    }
    rewind(fp);
    fscanf(fp, "%d %d", &nodes, &edges);
    for (int i = 0; i < edges; i++) {
        int src, dest;
        fscanf(fp, "%d %d", &src, &dest);
        adj_lists[src][adj_list_sizes[src]++] = dest;
        adj_lists[dest][adj_list_sizes[dest]++] = src;
    }
    fclose(fp);

    // 初始化广度优先搜索队列和已访问节点列表
    int* queue = malloc(nodes * sizeof(int));
    int queue_size = 0;
    int* visited = calloc(nodes, sizeof(int));

    // 开始广度优先搜索
    int level = 0;
    int level_size = 1;
    queue[queue_size++] = ROOT;
    visited[ROOT] = 1;
    while (level_size > 0) {
        #pragma omp parallel for schedule(dynamic)
        for (int i = 0; i < level_size; i++) {
            int curr = queue[i];
            for (int j = 0; j < adj_list_sizes[curr]; j++) {
                int neighbor = adj_lists[curr][j];
                if (!visited[neighbor]) {
                    visited[neighbor] = 1;
                    queue[queue_size++] = neighbor;
                }
            }
        }
        level++;
        level_size = queue_size - (level_size - 1);
    }

    // 输出遍历结果和运行时间
    if (rank == ROOT) {
        double end_time = MPI_Wtime();
        printf("Traversal took %f seconds.\n", end_time - start_time);
        printf("Visited nodes:");
        for (int i = 0; i < nodes; i++) {
            if (visited[i]) {
                printf(" %d", i);
            }
        }
        printf("\n");
    }

    // 释放内存并结束程序
    free(queue);
    free(visited);
    for (int i = 0; i < nodes; i++) {
        free(adj_lists[i]);
    }

    MPI_Finalize();
    return 0;
}

您可以使用以下命令编译并运行此代码：

mpicc -fopenmp bfs_mpi_openmp.c -o bfs_mpi_openmp
mpirun -np <num_procs> ./bfs_mpi_openmp <input_file>

其中 `<num_procs>` 是使用的MPI进程数，`<input_file>` 是输入文件名。

如果您需要更复杂的算法，建议阅读相关文献或咨询专业人士。