Compilare: user.cpp: In function ‘void bfs(int)’: user.cpp:36:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<v[x].size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:69:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j=0; j<a.size(); j++) ^ user.cpp:73:19: warning: suggest parentheses around assignment used as truth value [-Wparentheses] use[j]=f[j]=d[j]=0; ^