Compilare: user.cpp: In function ‘int main()’: user.cpp:32:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v1.size(); i++) { ^ user.cpp:34:106: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = std::lower_bound(v2.begin(),v2.end(), make_pair(v1[i].first,0)) - v2.begin(); j < v2.size(); j++) { ^ user.cpp:10:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("licenta.in","r",stdin); ^ user.cpp:11:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("licenta.out","w",stdout); ^ user.cpp:20:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&a,&b); ^ user.cpp:28:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&a,&b); ^