Compilare: main.cpp:28:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type] main() ^ main.cpp: In function 'int main()': main.cpp:75:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < plus.size(); i++) ~~^~~~~~~~~~~~~ main.cpp:95:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < plus.size(); i++) ~~^~~~~~~~~~~~~ main.cpp:97:8: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i < plus.size() - 1 && find(plus[i]) == find(minus[i]) && nr[find(plus[i])] == 1) ~~^~~~~~~~~~~~~~~~~