Compilare: user.cpp: In function ‘void dfs(std::vector<std::vector<int> >, int, int, int&, int&)’: user.cpp:14:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0; i<arb[node].size(); ++i) if (!visited[arb[node][i]]) ^ user.cpp: In function ‘int main()’: user.cpp:27:24: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf (fin, "%d", &n); ^ user.cpp:31:31: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf (fin, "%d%d", &a, &b); ^