Compilare: user.cpp: In function ‘int main()’: user.cpp:48:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int t=0;t<vec[cam[i]].size();t++){ ^ user.cpp:53:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int t=0;t<vec[1].size();t++) ^ user.cpp:17:9: warning: unused variable ‘ok’ [-Wunused-variable] int ok; ^