answer.code: In function ‘void dfs(long long int)’:
answer.code:44:21: error: invalid use of member function ‘constexpr std::vector<_Tp, _Alloc>::size_type std::vector<_Tp, _Alloc>::size() const [with _Tp = long long int; _Alloc = std::allocator<long long int>; size_type = long unsigned int]’ (did you forget the ‘()’ ?)
   44 |         if(reach[u].size==0){
      |            ~~~~~~~~~^~~~
      |                         ()
answer.code: In function ‘ll place_police(std::vector<long long int>, std::vector<long long int>, std::vector<long long int>)’:
answer.code:85:24: error: ‘n’ was not declared in this scope
   85 |         for(int i=1;i<=n;i++)
      |                        ^
answer.code:96:24: error: ‘n’ was not declared in this scope
   96 |         for(int i=1;i<=n;i++)
      |                        ^