merge($pairings) takes a list of pairs, each pair indicates the sameness of the two indexes. Returns a partitioned list of same indexes.
For example, if the input is merge( [ [1,2], [2,4], [5,6] ] );
that means 1 and 2 are the same. 2 and 4 are the same. Therefore 1==2==4. The result returned is
[[4,2,1],[6,5]];
Not sure how efficient this is, but I decided to take advantage of the operations provided by sets:
def merge(pairs):
pairs = set(tuple(sorted(p)) for p in pairings)
merged = []
# Each loop will result in a new, complete sublist in the result.
while pairs:
p = set(pairings.pop())
remove = set([])
for pair in pairs:
pairSet = set(pair)
if pairSet & p:
p |= pairSet
remove.add(pair)
pairs -= remove
merged.append(list(p))
return merged-- Brian Beck Adventurer of the First Order -- http://mail.python.org/mailman/listinfo/python-list
