Compilare: user.cpp: In function ‘int bfs()’: user.cpp:40:11: warning: unused variable ‘fiu’ [-Wunused-variable] int x,fiu; ^ user.cpp: In function ‘int main()’: user.cpp:91:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k=0;k<a.size();k++) ^ user.cpp:102:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a.size();i++) ^