Compilare: user.cpp: In function ‘int bfs(int)’: user.cpp:32:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<v[c[i]].size();j++) ^ user.cpp:21:9: warning: unused variable ‘a’ [-Wunused-variable] int a=0,i,k=0,k1=0,k2=0,poz,j; ^ user.cpp:21:19: warning: unused variable ‘k1’ [-Wunused-variable] int a=0,i,k=0,k1=0,k2=0,poz,j; ^ user.cpp:21:24: warning: unused variable ‘k2’ [-Wunused-variable] int a=0,i,k=0,k1=0,k2=0,poz,j; ^ user.cpp:21:29: warning: unused variable ‘poz’ [-Wunused-variable] int a=0,i,k=0,k1=0,k2=0,poz,j; ^ user.cpp:42:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^