Compilare: user.cpp: In function ‘int main()’: user.cpp:77:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < pos.size() ; ++ i) { ^ user.cpp:49:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(infile, "r", stdin); ^ user.cpp:50:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(outfile, "w", stdout); ^