Today's Challenge

https://leetcode.com/problems/palindrome-pairs/

Palindrome Pairs - LeetCode

Hard 난이도긴 한데.. n이 그렇게 크지 않아서 여러 번 loop 돌려서 처리 가능

class Solution:
    def palindromePairs(self, words: List[str]) -> List[List[int]]:
        backward, res = {}, []
    
        for i, word in enumerate(words):
            backward[word[::-1]] = i
            
        for i, word in enumerate(words):
            
            if word in backward and backward[word] != i:
                res.append([i, backward[word]])
                
            if word != "" and "" in backward and word == word[::-1]:
                res.append([i, backward[""]])
                res.append([backward[""], i])
                
            for j in range(len(word)):
                if word[j:] in backward and word[:j] == word[j-1::-1]:
                    res.append([backward[word[j:]], i])
                if word[:j] in backward and word[j:] == word[:j-1:-1]:
                    res.append([i, backward[word[:j]]])
            
        return res