Compilare: user.cpp: In function ‘bool cond(int)’: user.cpp:13:69: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] return (marked[nod]==1 && (val[nod]==0 || val[nod]>un[nod].size())); ^ user.cpp: In function ‘void mark(int)’: user.cpp:18:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k=0;k<v[nod].size();k++) ^ user.cpp: In function ‘int main()’: user.cpp:44:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k=0;k<v[x].size();k++) ^ user.cpp:54:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<ans.size();i++) ^