Compilare: user.cpp: In function ‘int main()’: user.cpp:11:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] #define sz size() ^ user.cpp:29:35: note: in expansion of macro ‘sz’ for (x=0;x<H[val].sz;x++) ^ user.cpp:11:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] #define sz size() ^ user.cpp:45:35: note: in expansion of macro ‘sz’ for (x=0;x<G[val].sz;x++) ^ user.cpp:11:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] #define sz size() ^ user.cpp:61:43: note: in expansion of macro ‘sz’ for (x=0;x<G[val].sz;x++) ^ user.cpp:11:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] #define sz size() ^ user.cpp:67:43: note: in expansion of macro ‘sz’ for (x=0;x<H[val].sz;x++) ^ user.cpp:11:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] #define sz size() ^ user.cpp:75:43: note: in expansion of macro ‘sz’ for (x=0;x<H[val].sz;x++) ^ user.cpp:18:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("oite.in","r",stdin); ^ user.cpp:19:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("oite.out","w",stdout); ^ user.cpp:21:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld %ld",&n,&k); ^ user.cpp:25:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld",&a[i]); ^