我正在尝试找到一种优雅/有效的解决方案,以在具有一定约束的情况下在列表中查找子列表。
例如,给定以下列表:
values = ['a', 'b', 'c', 'd', 'e', 'f']
以及maxLength的值:
maxLength = 4
找到值列表中的所有子列表,使得:
因此在此示例中,这些是可接受的解决方案:
[['a'], ['b'], ['c'], ['d'], ['e'], ['f']]
[['a', 'b'], ['c'], ['d'], ['e'], ['f']]
...
[['a', 'b'], ['c', 'd', 'e'], ['f']]
...
[['a', 'b', 'c', 'd'], ['e', 'f']]
...
[['a', 'b'], ['c', 'd', 'e', 'f']]
这些是不可接受的:
[['a', 'b'], ['d', 'e'], ['f']] #Error: not consecutive, 'c' is missing
[['a', 'b', 'c'], ['c', 'd', 'e'], ['f']] #Error: overlapping, 'c' is in two subsets
[['a', 'b', 'c', 'd', 'e'], ['f']] #Error: the first sublist has length > maxLength (4)
答案 0 :(得分:3)
您可以使用递归:
values = ['a', 'b', 'c', 'd', 'e', 'f']
maxLength = 4
def groupings(d):
if not d:
yield []
else:
for i in range(1, maxLength+1):
for c in groupings(d[i:]):
yield [d[:i], *c]
_d = list(groupings(values))
new_d = [a for i, a in enumerate(_d) if a not in _d[:i]]
输出:
[[['a'], ['b'], ['c'], ['d'], ['e'], ['f']], [['a'], ['b'], ['c'], ['d'], ['e', 'f']], [['a'], ['b'], ['c'], ['d', 'e'], ['f']], [['a'], ['b'], ['c'], ['d', 'e', 'f']], [['a'], ['b'], ['c', 'd'], ['e'], ['f']], [['a'], ['b'], ['c', 'd'], ['e', 'f']], [['a'], ['b'], ['c', 'd', 'e'], ['f']], [['a'], ['b'], ['c', 'd', 'e', 'f']], [['a'], ['b', 'c'], ['d'], ['e'], ['f']], [['a'], ['b', 'c'], ['d'], ['e', 'f']], [['a'], ['b', 'c'], ['d', 'e'], ['f']], [['a'], ['b', 'c'], ['d', 'e', 'f']], [['a'], ['b', 'c', 'd'], ['e'], ['f']], [['a'], ['b', 'c', 'd'], ['e', 'f']], [['a'], ['b', 'c', 'd', 'e'], ['f']], [['a', 'b'], ['c'], ['d'], ['e'], ['f']], [['a', 'b'], ['c'], ['d'], ['e', 'f']], [['a', 'b'], ['c'], ['d', 'e'], ['f']], [['a', 'b'], ['c'], ['d', 'e', 'f']], [['a', 'b'], ['c', 'd'], ['e'], ['f']], [['a', 'b'], ['c', 'd'], ['e', 'f']], [['a', 'b'], ['c', 'd', 'e'], ['f']], [['a', 'b'], ['c', 'd', 'e', 'f']], [['a', 'b', 'c'], ['d'], ['e'], ['f']], [['a', 'b', 'c'], ['d'], ['e', 'f']], [['a', 'b', 'c'], ['d', 'e'], ['f']], [['a', 'b', 'c'], ['d', 'e', 'f']], [['a', 'b', 'c', 'd'], ['e'], ['f']], [['a', 'b', 'c', 'd'], ['e', 'f']]]