def eliminate(g, eqs, eq):
rowp = [eq]
remaining_eqs = sorted(n for n in g if n in eqs and n != eq)
heap = PriorityQueue()
heap.populate((r, len(g[r])) for r in remaining_eqs)
elimination_step(g, heap, eq)
while heap:
eq, nzeros = heap.peekitem()
if nzeros > 1:
break
heap.popitem()
rowp.append(eq)
elimination_step(g, heap, eq)
return rowp, heap
def eliminate(g, remaining_eqs, eq):
rowp = [ eq ]
remaining_eqs.remove(eq)
heap = PriorityQueue()
heap.populate((r, len(g[r])) for r in sorted(remaining_eqs))
elimination_step(g, heap, eq)
while heap:
eq, nzeros = heap.peekitem()
if nzeros > 1:
break
remaining_eqs.remove(eq)
heap.popitem()
rowp.append(eq)
elimination_step(g, heap, eq)
return rowp, heap
def initial_solution(g_orig, eqs):
# Duplication of heap_md.min_degree with none forbidden
g = fast_copy(g_orig)
eq_nzeros = PriorityQueue()
eq_nzeros.populate((eq, len(g[eq])) for eq in sorted(eqs))
rowp, n_tears = [ ], len(g) - len(eqs)
while eq_nzeros:
nzeros, eq = eq_nzeros.popitem()
if nzeros:
n_tears -= 1
rowp.append(eq)
vrs = sorted(g[eq])
eqs_update = set(chain.from_iterable(g[v] for v in vrs))
eqs_update.discard(eq)
g.remove_node(eq)
g.remove_nodes_from(vrs)
for e in sorted(eqs_update):
eq_nzeros[e] = len(g[e])
assert len(rowp) == len(eqs)
return n_tears, rowp