Mã chấm: 97994

Main.cc: In function ‘int main()’:
Main.cc:14:17: error: ‘swap’ was not declared in this scope
                 swap(a[i],a[j]);
                 ^~~~
Main.cc:14:17: note: suggested alternatives:
In file included from /usr/include/c++/7/utility:70:0,
                 from /usr/include/c++/7/algorithm:60,
                 from Main.cc:2:
/usr/include/c++/7/bits/stl_pair.h:495:5: note:   ‘std::swap’
     swap(pair<_T1, _T2>& __x, pair<_T1, _T2>& __y)
     ^~~~
In file included from /usr/include/c++/7/bits/stl_pair.h:59:0,
                 from /usr/include/c++/7/utility:70,
                 from /usr/include/c++/7/algorithm:60,
                 from Main.cc:2:
/usr/include/c++/7/bits/move.h:187:5: note:   ‘std::swap’
     swap(_Tp& __a, _Tp& __b)
     ^~~~
In file included from /usr/include/c++/7/exception:142:0,
                 from /usr/include/c++/7/new:40,
                 from /usr/include/c++/7/bits/stl_construct.h:59,
                 from /usr/include/c++/7/bits/stl_tempbuf.h:60,
                 from /usr/include/c++/7/bits/stl_algo.h:62,
                 from /usr/include/c++/7/algorithm:62,
                 from Main.cc:2:
/usr/include/c++/7/bits/exception_ptr.h:166:5: note:   ‘std::__exception_ptr::swap’
     swap(exception_ptr& __lhs, exception_ptr& __rhs)
     ^~~~
Main.cc:5:10: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &n);
     ~~~~~^~~~~~~~~~
Main.cc:9:14: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d", &a[i]);
         ~~~~~^~~~~~~~~~~~~