Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:15:29: 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:63:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<G.size()&&ok;++j) ^ user.cpp:67:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<G.size();++j) ^ user.cpp:76:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<G.size()&&ok;++j) ^ user.cpp:80:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<A.size();++j) S[A[j]]+=i-S[a]; ^ user.cpp:81:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<G.size();++j) ^