Compilare: user.cpp: In function ‘void solve()’: user.cpp:40:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i<vec.size(); ++i) { ^ user.cpp:42:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = i+1; j<vec.size(); ++j) { ^ user.cpp:44:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (j<=vec[i].second) { ^ user.cpp:48:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int k = j+1; k<vec.size(); ++k) { ^ user.cpp:50:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (K<=vec[i].second) K = vec[i].first; ^ user.cpp:51:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (K<=vec[j].second) K = vec[j].first; ^