Compilare: main.cpp: In function 'void add_to_hash(const int&)': main.cpp:13:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<h[bucket].size();++i) ~^~~~~~~~~~~~~~~~~ main.cpp: In function 'int hash_search(const int&)': main.cpp:28:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<h[bucket].size();++i) ~^~~~~~~~~~~~~~~~~ main.cpp: In function 'void read()': main.cpp:36:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("take5.in", "r", stdin); ^ main.cpp:37:29: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &sum); ^ main.cpp:39:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &v[i]); ^ main.cpp:60:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("take5.out", "w", stdout); ^