foo.cpp:1:2: error: stray '#' in program
 2#include<cstdio>
  ^
foo.cpp:1:1: error: expected unqualified-id before numeric constant
 2#include<cstdio>
 ^
In file included from C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/cmath:43:0,
                 from foo.cpp:2:
C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/ext/type_traits.h:160:35: error: '__gnu_cxx::__is_null_pointer' declared as an 'inline' variable
   __is_null_pointer(std::nullptr_t)
                                   ^
C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/ext/type_traits.h:160:35: error: 'bool __gnu_cxx::__is_null_pointer' redeclared as different kind of symbol
C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/ext/type_traits.h:155:5: note: previous declaration 'template<class _Type> bool __gnu_cxx::__is_null_pointer(_Type)'
     __is_null_pointer(_Type)
     ^
C:/TDM-GCC-32/lib/gcc/mingw32/4.9.2/include/c++/ext/type_traits.h:160:21: error: 'nullptr_t' is not a member of 'std'
   __is_null_pointer(std::nullptr_t)
                     ^
foo.cpp: In function 'int main()':
foo.cpp:34:30: error: 'scanf' was not declared in this scope
  scanf("%d%d%d%d",&s,&t,&a,&b);
                              ^
foo.cpp:65:22: error: 'printf' was not declared in this scope
  printf("%.2lf\n",ans);
                      ^