molecules.cpp: In function 'std::vector<int> find_subset(int, int, std::vector<long long int>)':
molecules.cpp:20:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
while(ptr<pw.size())
~~~^~~~~~~~~~
molecules.cpp:33:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i=0;i<ans.size() && pw.size()-1-i>=ans.size();i++)
~^~~~~~~~~~~
/tmp/ccEX8n5Y.o: In function `main':
grader.cpp:(.text.startup+0x152): undefined reference to `find_subset(int, int, std::vector<int, std::allocator<int> >)'
collect2: error: ld returned 1 exit status