foo.cc: In function 'void dfs(int, int, int, int*)':
foo.cc:30:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int k=0;k<v[i].size();k++){
              ~^~~~~~~~~~~~
foo.cc: In function 'int main()':
foo.cc:63:39: error: no matching function for call to 'min(long long int&, int)'
    else res=min(res,a[i].l-dis[au][av]);
                                       ^
In file included from /usr/include/c++/7/bits/char_traits.h:39:0,
                 from /usr/include/c++/7/ios:40,
                 from /usr/include/c++/7/ostream:38,
                 from /usr/include/c++/7/iostream:39,
                 from foo.cc:1:
/usr/include/c++/7/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++/7/bits/stl_algobase.h:195:5: note:   template argument deduction/substitution failed:
foo.cc:63:39: note:   deduced conflicting types for parameter 'const _Tp' ('long long int' and 'int')
    else res=min(res,a[i].l-dis[au][av]);
                                       ^
In file included from /usr/include/c++/7/bits/char_traits.h:39:0,
                 from /usr/include/c++/7/ios:40,
                 from /usr/include/c++/7/ostream:38,
                 from /usr/include/c++/7/iostream:39,
                 from foo.cc:1:
/usr/include/c++/7/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++/7/bits/stl_algobase.h:243:5: note:   template argument deduction/substitution failed:
foo.cc:63:39: note:   deduced conflicting types for parameter 'const _Tp' ('long long int' and 'int')
    else res=min(res,a[i].l-dis[au][av]);
                                       ^
In file included from /usr/include/c++/7/algorithm:62:0,
                 from foo.cc:5:
/usr/include/c++/7/bits/stl_algo.h:3450:5: note: candidate: template<class _Tp> _Tp std::min(std::initializer_list<_Tp>)
     min(initializer_list<_Tp> __l)
     ^~~
/usr/include/c++/7/bits/stl_algo.h:3450:5: note:   template argument deduction/substitution failed:
foo.cc:63:39: note:   mismatched types 'std::initializer_list<_Tp>' and 'long long int'
    else res=min(res,a[i].l-dis[au][av]);
                                       ^
In file included from /usr/include/c++/7/algorithm:62:0,
                 from foo.cc:5:
/usr/include/c++/7/bits/stl_algo.h:3456:5: 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++/7/bits/stl_algo.h:3456:5: note:   template argument deduction/substitution failed:
foo.cc:63:39: note:   mismatched types 'std::initializer_list<_Tp>' and 'long long int'
    else res=min(res,a[i].l-dis[au][av]);
                                       ^
foo.cc:39:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&n,&m);
  ~~~~~^~~~~~~~~~~~~~
foo.cc:40:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(int i=0;i<m;i++)scanf("%d%d%d",&a[i].u,&a[i].v,&a[i].l);
                      ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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