Python 2 code for Leetcode 765

leetcode_765.py

def convert_to_couples(row):
    return [n // 2 for n in row]

def trim_couples(couples):
    return [
        couples[i] for i in xrange(len(couples))
        if couples[i//2*2] != couples[i//2*2+1]
    ]

def reindex_by_appearance(sequence):
    seen = dict()
    result = list()
    index = 0

    for val in sequence:
        if val in seen:
            result.append(seen.get(val))
        else:
            result.append(index)
            seen[val] = index
            index += 1
    return result

def get_diff_count(seq_a, seq_b):
    return sum(1 for i in xrange(len(seq_a)) if seq_a[i] != seq_b[i])

def min_swaps(seq):
    couples = convert_to_couples(seq)
    trimmed_couples = trim_couples(couples)
    reindexed_couples = reindex_by_appearance(trimmed_couples)
    sorted_couples = sorted(reindexed_couples)
    return int(round(get_diff_count(reindexed_couples, sorted_couples) / 2.0))

def decouple(couples):
    seen = set()
    result = list()
    for member in couples:
        if member in seen:
            result.append(2*member+1)
        else:
            result.append(2*member)
            seen.add(member)
    return result

Not sure what Leetcode problem #765 is, what this does, what the main method is (I think min_swaps, not sure what decouple does), or whether the solution above works.

I just know I worked on this a while ago (in a conversation with a friend), have this file on my computer (clarification: this is my own solution, and my own code, I just don't remember any of the context), and want to free up the space so I'm just putting it it a gist.

Enjoy.