//C++ 随机字符串生成函数  #include<iostream>  #include<ctime>  using namespace std;    const int LEN_NAME=4;    char *rand_str(char *str,const int len)  {      int i;      for(i=0;i<len;++i)          str[i]='A'+rand()%26;      str[++i]='\0';      return str;  }    void main()  {      srand(time(NULL));      int i;      char name[LEN_NAME+1];        for(i=0;i<20;++i)      {          cout<<rand_str(name,LEN_NAME)<<endl;      }  }