Compilare: user.cpp: In function ‘int main()’: user.cpp:39:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (sol.size() < n) { ^ user.cpp:41:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < P.size(); ++i) ^ user.cpp:47:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < P.size(); ++i) { ^ user.cpp:52:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < P.size(); ++i) ^ user.cpp:62:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 2; i < P.size(); ++i) { ^