Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:13:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < g[u].size(); ++i) { ^ user.cpp: In function ‘int main()’: user.cpp:24:28: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d%d", &n, &m); ^ user.cpp:26:30: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d%d", &x, &y); ^