':type words: List[str]
:rtype: List[List[int]]'

def palindromePairs(self, words):

    res = []
    trie = TrieNode()
    for i in xrange(len(words)):
        trie.insert(words[i], i)
    for i in xrange(len(words)):
        trie.find(words[i], i, res)
    return res
