molecules.cpp: In function 'std::vector<int> find_subset(int, int, std::vector<int>)':
molecules.cpp:35:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i = 0 ; i < w.size() ; ++i) v.push_back({w[i] , i});
~~^~~~~~~~~~
molecules.cpp:37:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i = 0 ; i < w.size() ; ++i){
~~^~~~~~~~~~
molecules.cpp:42:4: error: return-statement with no value, in function returning 'std::vector<int>' [-fpermissive]
return;
^~~~~~