Compilare: user.cpp: In function ‘void add(int, int)’: user.cpp:13:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<HASH[y].size();j++) ^ user.cpp: In function ‘int find(int)’: user.cpp:26:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j=0;j<HASH[y].size();j++) ^ user.cpp: In function ‘int main()’: user.cpp:38:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("patrate6.in","r",stdin); ^ user.cpp:39:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("patrate6.out","w",stdout); ^ user.cpp:40:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:43:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&x); ^