编写MPI程序，判断素数,进程0读取输入的n个整数（其中n刚好是进程数的倍数),并将这些整数平均分配到各个进程，最后进程0打印所有素数。

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

int is_prime(int n) {
    if (n < 2) return 0;
    for (int i = 2; i * i <= n; i++) {
        if (n % i == 0) return 0;
    }
    return 1;
}

int main(int argc, char** argv) {
    MPI_Init(&argc, &argv);

    int rank, size;
    MPI_Comm_rank(MPI_COMM_WORLD, &rank);
    MPI_Comm_size(MPI_COMM_WORLD, &size);

    int n;
    if (rank == 0) {
        printf("请输入n：");
        scanf("%d", &n);
        if (n % size != 0) {
            printf("n必须是进程数的倍数\n");
            MPI_Finalize();
            return 0;
        }
    }
    MPI_Bcast(&n, 1, MPI_INT, 0, MPI_COMM_WORLD);

    int* nums = (int*)malloc(sizeof(int) * (n / size));
    MPI_Scatter(nums, n / size, MPI_INT, nums, n / size, MPI_INT, 0, MPI_COMM_WORLD);

    int count = 0;
    for (int i = 0; i < n / size; i++) {
        if (is_prime(nums[i])) count++;
    }
    int* counts = (int*)malloc(sizeof(int) * size);
    MPI_Gather(&count, 1, MPI_INT, counts, 1, MPI_INT, 0, MPI_COMM_WORLD);

    if (rank == 0) {
        printf("素数：");
        for (int i = 0; i < n / size * size; i++) {
            int num;
            scanf("%d", &num);
            if (is_prime(num)) printf("%d ", num);
        }
        printf("\n");
    }

    free(nums);
    free(counts);
    MPI_Finalize();
    return 0;
}