Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:68:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < list[node].size(); i++) { ^ user.cpp: In function ‘int main()’: user.cpp:105:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("invtree.in", "r", stdin); ^ user.cpp:106:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("invtree.out", "w", stdout); ^ user.cpp:108:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld%lld", &n, &H); ^ user.cpp:110:42: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld%lld%lld", &x, &y, &z); ^