Compilare: main.cpp: In function 'bool vf(int)': main.cpp:63:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=1; i<=robot1.size(); i++) ~^~~~~~~~~~~~~~~ main.cpp:68:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=1; j<=robot2.size(); j++) ~^~~~~~~~~~~~~~~ main.cpp:84:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=1; j<=robot2.size(); j++) ~^~~~~~~~~~~~~~~ main.cpp:116:1: warning: control reaches end of non-void function [-Wreturn-type] } ^