Compilare: main.cpp: In function 'void filter()': main.cpp:125:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 1; j < circles.size(); ++j) ~~^~~~~~~~~~~~~~~~ main.cpp:130:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (i < dirs.size() && eq(dirs[i], start)) { ~~^~~~~~~~~~~~~ main.cpp:134:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (i < dirs.size()) { ~~^~~~~~~~~~~~~