Compilare: user.cpp: In function ‘bool exista(int)’: user.cpp:19:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(t > sir[i].size()) ^ user.cpp:25:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = t; j < sir[i].size(); j++) ^ user.cpp: In function ‘int caut_bin()’: user.cpp:98:1: warning: control reaches end of non-void function [-Wreturn-type] } ^