Compilare: user.cpp: In function ‘void dell(line)’: user.cpp:46:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<S.size();i++) ~^~~~~~~~~ user.cpp:48:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (;i+1<S.size();i++) S[i] = S[i+1]; ~~~^~~~~~~~~ user.cpp: In function ‘int UPline(int, int)’: user.cpp:60:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<S.size();i++){ ~^~~~~~~~~ user.cpp: In function ‘int ONline(int, int)’: user.cpp:68:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<S.size();i++) if (abs(getY(S[i],x) - y)<eps) return 1; ~^~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:81:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j=0;j<M[P[i].x].size();j++) ~^~~~~~~~~~~~~~~~~