在sem_wait(&sem)和sem_post(&sem)之间加上printf("\n")，报段错误 (核心已转储)

问题遇到的现象和发生背景

在sem_wait(&sem)和sem_post(&sem)之间加上printf("\n")，报段错误 (核心已转储)

代码块

#include
#include
#include
int num;
sem_t sem[4];
void* pthread_main1()
{
    for(int i=0;i_wait(&sem[0]);
        printf("I ");
        sem_post(&sem[1]);
    }

}
void* pthread_main2()
{
    for(int i=0;i_wait(&sem[1]);    
    printf("Love ");
    sem_post(&sem[2]);
    }
    
}
void* pthread_main3()
{
    for(int i=0;i_wait(&sem[2]);    
        printf("Jinan ");
        sem_post(&sem[3]);
    }
    
} 
void* pthread_main4()
{
    for(int i=0;i_wait(&sem[3]);    
    printf("University! \n ");
    sem_post(&sem[0]);
    }
    
}
 
void init_sems()
{
    for (int i = 0; i < 4; i++)
    {
        if(i==0)
        {
            sem_init(sem+i,0,1);
        }
        else
        {
            sem_init(sem+i,0,0);
        }
    }
    
}

 
int main()
{

    int i=0;
    printf("please enter the count:");
    scanf("%d",&num);
    init_sems();
    pthread_t pid[4];
    pthread_create((void*)&(pid[0]),NULL,(void*)pthread_main1,NULL);
    pthread_create((void*)&(pid[1]),NULL,(void*)pthread_main2,NULL);
    pthread_create((void*)&(pid[1]),NULL,(void*)pthread_main3,NULL);
    pthread_create((void*)&(pid[1]),NULL,(void*)pthread_main4,NULL);
    for(i=0;i<4;i++)
    {
        pthread_join(pid[i],NULL);
    }


    sem_destroy(&sem[0]);
    sem_destroy(&sem[1]);
    sem_destroy(&sem[2]);
    sem_destroy(&sem[3]);
    return 0;
}

错误发生在pthread_main4,我想换行打印，但直接报错