Function rot90

examples/pentominoes.cpp:897–902

  }
  template<class CArray, class Array>
  void rot90(CArray t1, int w1, int h1, Array t2, int& w2, int& h2) {
    w2 = h1; h2 = w1;
    for (int h = 0; h < h1; ++h)
      for (int w = 0; w < w1; ++w)
	t2[pos(w, w2-h-1, h2, w2)] = t1[pos(h, w, h1, w1)];
  }
  template<class CArray, class Array>
  void rot180(CArray t1, int w1, int h1, Array t2, int& w2, int& h2) {
    w2 = w1; h2 = h1;