Compilare: user.cpp: In function ‘void dfs(int, long long int)’: user.cpp:30:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < l[node].size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:60:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < nodes.size(); i++) ^ user.cpp:36:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("tempest.in", "r", stdin); ^ user.cpp:37:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("tempest.out", "w", stdout); ^ user.cpp:38:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &t); ^ user.cpp:41:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d", &n, &m, &s, &d); ^ user.cpp:43:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%lld", &x, &y, &z); ^ user.cpp:49:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &k); ^ user.cpp:52:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &x); ^