def unfuse_gridded_perm(
self, gp: GriddedPerm, left_points: Optional[int] = None
) -> Iterator[GriddedPerm]:
"""
Generator of all the possible ways to unfuse a gridded permutations.
If left_points is given, the iterator contains only one gridded
permutations with said number of left points.
"""
def stretch_above(p):
return p if p[1] < self._row_idx else (p[0], p[1] + 1)
def stretch_left(p):
return p if p[0] < self._col_idx else (p[0] + 1, p[1])
if self._fuse_row:
stretch = stretch_above
editable_pos_idx = [
i for i, p in enumerate(gp.pos) if p[1] == self._row_idx
]
editable_pos_idx.sort(key=lambda i: gp.patt[i])
else:
stretch = stretch_left
editable_pos_idx = [
i for i, p in enumerate(gp.pos) if p[0] == self._col_idx
]
editable_pos_idx.sort()
pos = list(map(stretch, gp.pos))
if left_points is None or left_points == 0:
yield gp.__class__(gp.patt, pos)
if left_points == 0:
return
row_shift = int(self._fuse_row)
col_shift = 1 - int(self._fuse_row)
for left_points_so_far, i in enumerate(editable_pos_idx):
pos[i] = (pos[i][0] - col_shift, pos[i][1] - row_shift)
if left_points is None or left_points_so_far + 1 == left_points:
yield gp.__class__(gp.patt, pos)
if left_points_so_far + 1 == left_points:
break
def fuse_gridded_perm(self, gp: GriddedPerm) -> GriddedPerm:
"""
Fuse the gridded permutation `gp`.
"""
fused_pos = []
for x, y in gp.pos:
if self._fuse_row and y > self._row_idx:
y -= 1
elif not self._fuse_row and x > self._col_idx:
x -= 1
fused_pos.append((x, y))
return gp.__class__(gp.patt, fused_pos)