Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:10:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j=0;j<graph[vertex].size();j++) ^ user.cpp: In function ‘int main()’: user.cpp:20:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("asmax.in", "r", stdin); ^ user.cpp:21:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("asmax.out", "w", stdout); ^ user.cpp:22:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:24:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &v[i]); ^ user.cpp:27:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^