Method insert

Math/Basis Vector.cpp:17–28

    clear();
  }
  void insert(T x) {
    for (int i = B - 1; i >= 0; i--) {
      if (x >> i & 1) {
        if (basis[i]) x ^= basis[i];
        else {
          basis[i] = x;
          sz++;
          break;
        }
      }
    }
  }
  // is there any subset having xor = x
  bool can(T x) {
    for(int i = B - 1; i >= 0; i--) {