Compilare: user.cpp: In function ‘int main()’: user.cpp:26:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<a[v[x]].size();j++) ^ user.cpp:12:17: warning: unused variable ‘b’ [-Wunused-variable] int n,m,s,i,b,x,j,c; ^ user.cpp:12:23: warning: unused variable ‘c’ [-Wunused-variable] int n,m,s,i,b,x,j,c; ^ user.cpp:31:27: warning: ‘x’ may be used uninitialized in this function [-Wmaybe-uninitialized] d[v[k]]=d[v[x]]+1;} ^