Compilare: user.cpp: In member function ‘bool SegmentTree::Check(int, int)’: user.cpp:80:17: warning: unused variable ‘mid’ [-Wunused-variable] int mid = l + (r - l) / 2; ^ user.cpp:96:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = p0; i < P.size() && Pj[P[i]] < Pj[p2]; ++i) ^ user.cpp: In function ‘long long int MaxArea()’: user.cpp:165:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (j + 1 >= Pi.size() || Pi[j + 1].x != Pi[j].x) ^ user.cpp:169:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (i2 + 1 >= Pj.size() || Pj[i2 + 1].y != Pj[i2].y) ^ user.cpp:173:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (j2 + 1 >= Pi.size() || Pi[j2 + 1] != Pj[i2 + 1]) ^ user.cpp:155:24: warning: unused variable ‘cnt’ [-Wunused-variable] long long amax{0}, cnt{0}; ^ user.cpp: In function ‘int BinarySearch(Point, std::vector<Point>&, char)’: user.cpp:193:26: warning: narrowing conversion of ‘((& P)->std::vector<_Tp, _Alloc>::size<Point, std::allocator<Point> >() + 4294967295u)’ from ‘std::vector<Point>::size_type {aka unsigned int}’ to ‘int’ inside { } [-Wnarrowing] int l{0}, r{P.size() - 1}, mid; ^