Compilare: user.cpp: In function ‘void doit(int, int, char)’: user.cpp:12:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=start;i<=stop&&i<a.size();++i) ^ user.cpp:14:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(a[i].second==sign&&i<a.size()) ^ user.cpp: In function ‘int main()’: user.cpp:54:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a.size();++i) ^ user.cpp:28:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("evaluare.in","r",stdin); ^ user.cpp:29:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("evaluare.out","w",stdout); ^