Compilare: main.cpp: In function 'int main()': main.cpp:3:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] #define loop(i,a,b) for(int i=a;i<b;i++) main.cpp:51:13: loop(i,0,v.size()){ ~~~~~~~~~~~~ main.cpp:51:8: note: in expansion of macro 'loop' loop(i,0,v.size()){ ^~~~