Compilare: main.cpp: In function 'int main()': main.cpp:39:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (idx < events.size() && events[idx].x == i){ ~~~~^~~~~~~~~~~~~~~ main.cpp:43:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (idx >= events.size()) ~~~~^~~~~~~~~~~~~~~~