Language: C++

#include <bits/stdc++.h>
#define rep(i, n) for(int i=0; i<(int)(n); ++i)
using namespace std;

vector<bool> seen;
int color_num;

void dfs(const vector<vector<int>> &G, vector<vector<int>> &color, int v){
  seen[v] = true;
  for(auto next_v : G[v]){
    if(seen[next_v] == true) continue;
    color.at(next_v).push_back(color_num);
    -- color_num//todo
    dfs(G, color, next_v);
  }
}

int main(){
  int n;
  cin >> n;
  vector<vector<int>> G(n);
  rep(i, n-1){
    int a, b;
    cin >> a >> b;
    G[a-1].push_back(b-1);
    G[b-1].push_back(a-1);
  }
  
  int gmaxsize = 0;
  rep(i, n) gmaxsize = max(gmaxsize, G.at(i).size());
  color_num = gmaxsize;
  
  vector<vector<int>> color(n);
  
}


Compiler output:
a.cc: In function 'void dfs(const std::vector<std::vector<int> >&, std::vector<std::vector<int> >&, int)':
a.cc:13:17: error: expected ';' before 'dfs'
   13 |     -- color_num//todo
      |                 ^
      |                 ;
   14 |     dfs(G, color, next_v);
      |     ~~~          
a.cc: In function 'int main()':
a.cc:30:27: error: no matching function for call to 'max(int&, std::vector<int>::size_type)'
   30 |   rep(i, n) gmaxsize = max(gmaxsize, G.at(i).size());
      |                        ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/14/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:51,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_algobase.h:257:5: note: candidate: 'template<class _Tp> constexpr const _Tp& std::max(const _Tp&, const _Tp&)'
  257 |     max(const _Tp& __a, const _Tp& __b)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:257:5: note:   template argument deduction/substitution failed:
a.cc:30:27: note:   deduced conflicting types for parameter 'const _Tp' ('int' and 'std::vector<int>::size_type' {aka 'long unsigned int'})
   30 |   rep(i, n) gmaxsize = max(gmaxsize, G.at(i).size());
      |                        ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note: candidate: 'template<class _Tp, class _Compare> constexpr const _Tp& std::max(const _Tp&, const _Tp&, _Compare)'
  303 |     max(const _Tp& __a, const _Tp& __b, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note:   candidate expects 3 arguments, 2 provided
In file included from /usr/include/c++/14/algorithm:61:
/usr/include/c++/14/bits/stl_algo.h:5706:5: note: candidate: 'template<class _Tp> constexpr _Tp std::max(initializer_list<_Tp>)'
 5706 |     max(initializer_list<_Tp> __l)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5706:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_algo.h:5716:5: note: candidate: 'template<class _Tp, class _Compare> constexpr _Tp std::max(initializer_list<_Tp>, _Compare)'
 5716 |     max(initializer_list<_Tp> __l, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5716:5: note:   template argument deduction/substitution failed:
a.cc:30:27: note:   mismatched types 'std::initializer_list<_Tp>' and 'int'
   30 |   rep(i, n) gmaxsize = max(gmaxsize, G.at(i).size());
      |                        ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~