Compilare: user.cpp: In function ‘double naive(std::vector<point*>)’: user.cpp:41:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < pts.size() - 1; i++) { ^ user.cpp:42:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = i + 1; j < pts.size(); j++) { ^ user.cpp: In function ‘double min_strip_distance(std::vector<point*>, double)’: user.cpp:55:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < strip.size(); i++) { ^ user.cpp:56:44: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = i + 1; j < strip.size() && (strip[j]->y - strip[i]->y <= dist); j++) { ^