/in/foo.cc: In function 'void change(std::vector<int>)':
/in/foo.cc:21:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < p.size(); i++) {
                  ~~^~~~~~~~~~
/in/foo.cc:22:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int j = i + 1; j < p.size(); j++) {
                       ~~^~~~~~~~~~
/in/foo.cc: In function 'void add(std::vector<int>)':
/in/foo.cc:31:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  if (p.size() >= lim) return;
      ~~~~~~~~~^~~~~~
/in/foo.cc:32:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < p.size(); i++) {
                  ~~^~~~~~~~~~
/in/foo.cc: In function 'void delt(std::vector<int>)':
/in/foo.cc:74:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < p.size(); i++) {
                  ~~^~~~~~~~~~
/in/foo.cc:84:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   else if (i == p.size() - 1) {
            ~~^~~~~~~~~~~~~~~
/in/foo.cc: In function 'void bfs()':
/in/foo.cc:106:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if (h.k.size() > lim) continue;
       ~~~~~~~~~~~^~~~~