def test_row_reading_word():
t = Tableau()
assert t.row_reading_word() == tuple()
assert t == Tableau.from_row_reading_word(t.row_reading_word())
t = Tableau({(1, 1): 1, (1, 2): 3, (1, 3): 4, (2, 1): 2})
assert t.row_reading_word() == (2, 1, 3, 4)
u = Tableau.from_row_reading_word(t.row_reading_word())
assert t == u
def irsk(pi, n=None):
if n is None:
n = pi.rank
cycles = sorted([(pi(i), i) for i in range(1, n + 1) if i <= pi(i)])
tab = Tableau()
for b, a in cycles:
if a == b:
tab = tab.add(1, tab.max_column() + 1, a)
else:
p, q = InsertionAlgorithm.hecke(tab.row_reading_word() + (a, ))
i, j = q.find(len(q))[0]
while j > 1 and (i + 1, j - 1) not in p:
j = j - 1
tab = p.add(i + 1, j, b)
return tab
