ランダム化連鎖配列の本来の並び順を求める ref: https://qiita.com/kkdd/items/1a6968d9a45f3358d4f6

file0.txt

$ ./sequence_sort.py
 [[2, 3], [1, 2], [0, 1]] ==>
[0, 1]
[1, 2]
[2, 3]

sequence_sort.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

import random

SKIP = -1

def find_vacancy(seq):
    return list(set(range(len(seq))) - set(seq))[0]

def seq_nexts(arr):
    heads = [a[0] for a in arr]
    nexts = [heads.index(a[-1]) if a[-1] in heads else SKIP for a in arr]
    index_top = find_vacancy(nexts)
    return index_top, nexts

def sequence_sort(arr):
    i, nexts = seq_nexts(arr)
    indices = []
    while i is not SKIP:
        indices.append(i)
        i = nexts[i]
    return indices

N = 3
data = [[i,i+1] for i in range(N)]
random.shuffle(data)
print(data, '==>')

for i in sequence_sort(data):
    print(data[i])
exit(0)