cc.cpp

// Coodinate Compression
// https://youtu.be/fR3W5IcBGLQ?t=8550
template<typename T=int>
struct CC {
  bool initialized;
  vector<T> xs;
  CC(): initialized(false) {}
  void add(T x) { xs.push_back(x);}
  void init() {
    sort(xs.begin(), xs.end());
    xs.erase(unique(xs.begin(),xs.end()),xs.end());
    initialized = true;
  }
  int operator()(T x) {
    if (!initialized) init();
    return upper_bound(xs.begin(), xs.end(), x) - xs.begin() - 1;
  }
  T operator[](int i) {
    if (!initialized) init();
    return xs[i];
  }
  int size() {
    if (!initialized) init();
    return xs.size();
  }
};