windows下如何获取系统已存在的盘符 【c++】

 #include <iostream>
 #include "classAh.h"
 #include <atlstr.h>
 using namespace std;

 int main()
 {
     char rootPath[] = {}, driveType[] = {};
     UINT nType;  

     for(char a = 'A'; a <= 'Z'; a++)
     {
         sprintf(rootPath, "%c:\\", a);
         nType = GetDriveType(rootPath);
         if(nType != DRIVE_NO_ROOT_DIR)                  // DRIVE_NO_ROOT_DIR: 路径无效
         {
             switch(nType)
             {
             case DRIVE_FIXED:
                 strcpy(driveType, "硬盘");
                 break;
             case DRIVE_REMOVABLE:
                 strcpy(driveType, "移动硬盘");
                 break;
             case DRIVE_CDROM:
                 strcpy(driveType, "光盘");
                 break;
             case DRIVE_RAMDISK:
                 strcpy(driveType, "RAM盘");
                 break;
             case DRIVE_REMOTE:
                 strcpy(driveType, "Remote(Network) drive 网络磁盘");
                 break;
             case DRIVE_UNKNOWN:
             default:
                 strcpy(driveType, "未知盘");
                 break;
             }
             cout<<rootPath<<"\t"<<driveType<<endl;
         }
     }  

     getchar();
     return ;
 }