Compilare: main.cpp: In function 'int findh(int)': main.cpp:41:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < h[key].size() ; i ++) ~~^~~~~~~~~~~~~~~ main.cpp:40:9: warning: unused variable 'i' [-Wunused-variable] int i, key = x % MOD; ^ main.cpp: In function 'void updateh(int, int)': main.cpp:49:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < h[key].size() ; i ++) ~~^~~~~~~~~~~~~~~ main.cpp:48:9: warning: unused variable 'i' [-Wunused-variable] int i, key = x % MOD; ^ main.cpp: In function 'void eraseh(int)': main.cpp:56:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < h[key].size() ; i ++) ~~^~~~~~~~~~~~~~~ main.cpp:55:9: warning: unused variable 'i' [-Wunused-variable] int i, key = x % MOD; ^ main.cpp: In function 'void get_int(int&)': main.cpp:15:36: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(buffer, sz, 1, stdin); ^ main.cpp:23:36: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(buffer, sz, 1, stdin); ^ main.cpp: In function 'int main()': main.cpp:97:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("secv5.in", "r", stdin); ^ main.cpp:98:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("secv5.out", "w", stdout); ^