Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:34:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < list[node].size(); i++) { ^ user.cpp: In function ‘bool check(int)’: user.cpp:78:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] return sol.size() <= k; ^ user.cpp: In function ‘int main()’: user.cpp:84:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("salvare.in","r",stdin); ^ user.cpp:85:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("salvare.out","w",stdout); ^ user.cpp:87:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &k); ^ user.cpp:89:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^