Compilare: user.cpp: In function ‘int main()’: user.cpp:51:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("xormax.in","r",stdin); ^ user.cpp:52:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("xormax.out","w",stdout); ^ user.cpp:56:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n",&n); ^ user.cpp:59:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&x); ^ user.cpp: In function ‘int query(Trie*, int, int)’: user.cpp:47:1: warning: control reaches end of non-void function [-Wreturn-type] } ^