Given a list of unique words, find all pairs of distinct indices (i, j) in the given list, so that the concatenation of the two words, i.e. words[i] + words[j] is a palindrome.
Example 1:
Input: ["abcd","dcba","lls","s","sssll"]
Output: [[0,1],[1,0],[3,2],[2,4]]
Explanation: The palindromes are ["dcbaabcd","abcddcba","slls","llssssll"]
Example 2:
Input: ["bat","tab","cat"]
Output: [[0,1],[1,0]]
Explanation: The palindromes are ["battab","tabbat"]
336. Palindrome Pairs
Difficulty: Hard
Given a list of unique words, find all pairs of distinct indices
(i, j)in the given list, so that the concatenation of the two words, i.e.words[i] + words[j]is a palindrome.Example 1:
Example 2: