Compilare: user.cpp: In function ‘void index(std::vector<int>&, std::vector<int>&)’: user.cpp:56:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a.size();++i) ^ user.cpp:58:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<b.size();++i) ^ user.cpp:62:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a.size();++i){ ^ user.cpp:68:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<b.size();++i) { ^ user.cpp: In function ‘int main()’: user.cpp:76:24: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(fin,"r",stdin); ^ user.cpp:77:26: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(fout,"w",stdout); ^ user.cpp: In function ‘void cit(int&)’: user.cpp:19:59: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] if (poz == Dim) fread(lin, 1, Dim, stdin), poz=0; ^ user.cpp:23:57: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] if (poz == Dim) fread(lin, 1, Dim, stdin), poz=0; ^