/in/foo.cc: In function 'int main()':
/in/foo.cc:12:31: error: no matching function for call to 'min(int, int, int, int)'
    a[i][j]=min(i+1,n-i,j+1,n-j);
                               ^
In file included from /usr/include/c++/6/bits/char_traits.h:39:0,
                 from /usr/include/c++/6/ios:40,
                 from /usr/include/c++/6/istream:38,
                 from /usr/include/c++/6/sstream:38,
                 from /usr/include/c++/6/complex:45,
                 from /usr/include/c++/6/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/6/bits/stdc++.h:52,
                 from /in/foo.cc:1:
/usr/include/c++/6/bits/stl_algobase.h:195:5: note: candidate: template<class _Tp> const _Tp& std::min(const _Tp&, const _Tp&)
     min(const _Tp& __a, const _Tp& __b)
     ^~~
/usr/include/c++/6/bits/stl_algobase.h:195:5: note:   template argument deduction/substitution failed:
/in/foo.cc:12:31: note:   candidate expects 2 arguments, 4 provided
    a[i][j]=min(i+1,n-i,j+1,n-j);
                               ^
In file included from /usr/include/c++/6/bits/char_traits.h:39:0,
                 from /usr/include/c++/6/ios:40,
                 from /usr/include/c++/6/istream:38,
                 from /usr/include/c++/6/sstream:38,
                 from /usr/include/c++/6/complex:45,
                 from /usr/include/c++/6/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/6/bits/stdc++.h:52,
                 from /in/foo.cc:1:
/usr/include/c++/6/bits/stl_algobase.h:243:5: note: candidate: template<class _Tp, class _Compare> const _Tp& std::min(const _Tp&, const _Tp&, _Compare)
     min(const _Tp& __a, const _Tp& __b, _Compare __comp)
     ^~~
/usr/include/c++/6/bits/stl_algobase.h:243:5: note:   template argument deduction/substitution failed:
/in/foo.cc:12:31: note:   candidate expects 3 arguments, 4 provided
    a[i][j]=min(i+1,n-i,j+1,n-j);
                               ^
In file included from /usr/include/c++/6/algorithm:62:0,
                 from /usr/include/x86_64-linux-gnu/c++/6/bits/stdc++.h:65,
                 from /in/foo.cc:1:
/usr/include/c++/6/bits/stl_algo.h:3447:5: note: candidate: template<class _Tp> _Tp std::min(std::initializer_list<_Tp>)
     min(initializer_list<_Tp> __l)
     ^~~
/usr/include/c++/6/bits/stl_algo.h:3447:5: note:   template argument deduction/substitution failed:
/in/foo.cc:12:31: note:   mismatched types 'std::initializer_list<_Tp>' and 'int'
    a[i][j]=min(i+1,n-i,j+1,n-j);
                               ^
In file included from /usr/include/c++/6/algorithm:62:0,
                 from /usr/include/x86_64-linux-gnu/c++/6/bits/stdc++.h:65,
                 from /in/foo.cc:1:
/usr/include/c++/6/bits/stl_algo.h:3453:5: note: candidate: template<class _Tp, class _Compare> _Tp std::min(std::initializer_list<_Tp>, _Compare)
     min(initializer_list<_Tp> __l, _Compare __comp)
     ^~~
/usr/include/c++/6/bits/stl_algo.h:3453:5: note:   template argument deduction/substitution failed:
/in/foo.cc:12:31: note:   mismatched types 'std::initializer_list<_Tp>' and 'int'
    a[i][j]=min(i+1,n-i,j+1,n-j);
                               ^