Compilare: main.cpp: In function 'std::vector<std::pair<int, int> > Merge(std::vector<std::pair<int, int> >, std::vector<std::pair<int, int> >)': main.cpp:15:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<b.size() && b[i].first<x) ~^~~~~~~~~ main.cpp:19:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i<b.size() && b[i].first==x) ~^~~~~~~~~ main.cpp: In function 'int main()': main.cpp:29:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("ausoara.in","r",stdin); ^ main.cpp:30:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("ausoara.out","w",stdout); ^