Compilare: main.cpp: In function 'void introduce_in_apm(int)': main.cpp:26:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<v[x].size(); i++) ~^~~~~~~~~~~~ main.cpp: In function 'void apm(int)': main.cpp:101:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0; j<v[x].size(); j++) ~^~~~~~~~~~~~