如题,以前一直用vc6.0的,现在接触vs2005发现很多地方不一样,比如要加using namespace std才能用cin,cout,不然要写std::cin,std::cout,
头文件里面iostream.h也要写成iostream才能用,不然说“无法打开包括文件:“iostream.h”: No such file or directory”

问题1:在用math.h时也是一直出错“无法打开包括文件:“math.h”: No such file or directory”
问题2:使用sqrt函数: 如 long n;
for(int i=2;i<=sqrt(n);i++)
{ }
的时候提示““sqrt”: 对重载函数的调用不明确”
请高手指点是什么原因,怎么解决?

std 不是 vs2005 的問題, 是 C++ 新標準... 更新了 C++, 你會發現在 VC6 也是這樣.
------------------------------------------------------------------------------
[MSDN]: Standard C++ Library Header Files

The following Standard C++ Library header files are documented:

<algorithm>
<bitset>
<complex>

<deque>
<exception>
<fstream>

<functional>
<hash_map>
<hash_set>

<iomanip>
<ios>
<iosfwd>

<iostream>
<iso646.h>
<istream>

<iterator>
<limits>
<list>

<locale>
<map>
<memory>

<new>
<numeric>
<ostream>

<queue>
<set>
<sstream>

<stack>
<stdexcept>
<streambuf>

<string>
<strstream>
<utility>

<valarray>
<vector>

In addition, the following C++ wrappers are documented:

<cassert>
<cctype>
<cerrno>

<cfloat>
<ciso646>
<climits>

<clocale>
<cmath>
<csetjmp>

<csignal>
<cstdarg>
<cstddef>

<cstdio>
<cstdlib>
<cstring>

<ctime>
<cwchar>
<cwctype>

For more information about Standard C++ Library header files, see the Standard C++ Library Overview.

See Also
Other Resources
Standard C++ Library Reference