heap_push()

static int heap_push ( heap *  h, heap_item  hi  )

static

{
     int insert;
     unsigned i, fdim = h->fdim;

     for (i = 0; i < fdim; ++i) {
          h->ee[i].val += hi.ee[i].val;
          h->ee[i].err += hi.ee[i].err;
     }
     insert = h->n;
     if (++(h->n) > h->nalloc) {
          heap_resize(h, h->n * 2);
          if (!h->items) return FAILURE;
     }

     while (insert) {
          int parent = (insert - 1) / 2;
          if (KEY(hi) <= KEY(h->items[parent]))
               break;
          h->items[insert] = h->items[parent];
          insert = parent;
     }
     h->items[insert] = hi;
     return SUCCESS;
}