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

void *task1(void *data)
{
    int n = *((int *)data);
    int ret = 1;
    while (n)
    {
        ret *= n--;
    }
    // pthread_exit(&ret);
    return ret;
}

int main(int argc, char const *argv[])
{
    if (argc != 2)
    {
        printf("usage: ./%s 数字\n", argv[0]);
        return 1;
    }

    pthread_t tid;
    int num = atoi(argv[1]);
    pthread_create(&tid, NULL, task1, (void *)&num);

    int res;
    pthread_join(tid, &res);
    printf("%d\n", res);

    return 0;
}