message: Use size_t instead of int in WeightMinHeap
diff: @@ -1797,7 +1797,7 @@ struct WeightMinHeap
  {
  c.reserve(w.size());
  loc.resize(w.size());
  - for (int i=0; i<w.size(); ++i) { push(i); }
  + for (size_t i=0; i<w.size(); ++i) { push(i); }
  }
  int percolate_up(int pos, double val)
  @@ -1812,11 +1812,11 @@ struct WeightMinHeap
  int percolate_down(int pos, double val)
  {
  - while (2*pos+1 < c.size())
  + while (size_t(2*pos+1) < c.size())
  {
  - int left = 2*pos+1;
  - int right = left+1;
  - int tgt;
  + size_t left = 2*pos+1;
  + size_t right = left+1;
  + size_t tgt;
  if (right < c.size() && w[c[right]] < w[c[left]]) { tgt = right; }
  else { tgt = left; }
  if (w[c[tgt]] < val)
  