Compilare: user.cpp: In function ‘void read()’: user.cpp:11:15: warning: unused variable ‘x’ [-Wunused-variable] int i, j, x, y; ^ user.cpp: In function ‘void bfs()’: user.cpp:36:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<a[x].size(); i++){ ^