Compilare: user.cpp: In function ‘void add(double, double, int, int)’: user.cpp:39:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<h[ind].size();i++) if(h[ind][i].x-a<e && h[ind][i].y-b<e)break; ^ user.cpp:40:6: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i==h[ind].size()){ ^ user.cpp: In function ‘int main()’: user.cpp:55:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cerc.in","r", stdin); ^ user.cpp:56:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cerc.out", "w", stdout); ^