三个线程每个线程输出一个字符

#include<stdio.h>
#include<unistd.h>
#include<pthread.h>
#define NUM 3

int n=0;
pthread_mutex_t t_mutex;
pthread_cond_t t_cond;

void *Execute(void *p)
{
int i=0;
int para = (int)p;
for(;i<10;i++)
{
pthread_mutex_lock(&t_mutex);
while(para!= n)
pthread_cond_wait(&t_cond,&t_mutex);
printf("%c ",para +'A');
n = (n+1)%NUM;
pthread_cond_broadcast(&t_cond);
pthread_mutex_unlock(&t_mutex);
}
return (void *)0;
}

int main()
{
int i=0;
pthread_t thread[NUM];
for(;i<NUM;i++)
{
int ret = pthread_create(&thread[i],NULL,Execute,(void * )i);
if(ret != 0)
{
printf("create pthread failed \n");
break;
}
}
for(i=0;i<NUM;i++)
{
pthread_join(thread[i],NULL);
}
printf("\nmain thread finished\n");
}