(阿里笔试）使用多线程和sleep函数生成字符串的伪随机排列

写在前面：这是阿里巴巴2014校园招聘2013.9.22杭州站的笔试题目，下面分别给出windows和linux平台的c/c++版本。

1. C/C++（windows平台）

//生成字符串的伪随机排列
#include <stdio.h>
#include <Windows.h>
#include <process.h>
#include <string>

unsigned int __stdcall Fun(void* pM)
{
Sleep(10);
char ch = *(char*)pM;
putchar(ch);
return 0;
}

int main()
{
std::string str = "abcdefg";
HANDLE handle[7];
for(int i = 0; i < 7; ++i)
handle[i] = (HANDLE)_beginthreadex(NULL,0,Fun,&str[i],0,NULL);
WaitForMultipleObjects(7,handle,TRUE,INFINITE);
return 0;

}

2. C/C++（Linux平台）

注意编译连接时需要链接pthread库，即g++ XX.cpp -o XX -lpthread

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

void* thread(void* v)
{
char ch = *(char*)v;
sleep(1);
putchar(ch);
}

int main()
{
pthread_t id[7];
int i ,ret;
char str[] = "abcdefg";
for(i = 0; i < 7; ++i)
{
ret = pthread_create(&id[i],NULL,thread,&str[i]);
if(0 != ret)
{
printf("create pthread error\n");
i--;
}
}
for(i = 0; i < 7; ++i)
pthread_join(id[i],NULL);
printf("\n");
return 0;

}