Compilare: main.cpp: In function 'int main()': main.cpp:19:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<v[x].size(); ++i) ~^~~~~~~~~~~~ main.cpp:31:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<v[x].size(); ++i) ~^~~~~~~~~~~~ main.cpp:30:17: warning: unused variable 'ok' [-Wunused-variable] int ok=0; ^~ main.cpp:39:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<v[x].size(); ++i) ~^~~~~~~~~~~~ main.cpp:7:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("hashuri.in","r",stdin); ^ main.cpp:8:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("hashuri.out","w",stdout); ^