Leetcode 49. Group Anagrams

[medium]

Group Anagrams - LeetCode

Given an array of strings strs, group the anagrams together. You can return the answer in any order.

An Anagram is a word or phrase formed by rearranging the letters of a different word or phrase, typically using all the original letters exactly once.

Example 1:

Input: strs = ["eat","tea","tan","ate","nat","bat"]
Output: [["bat"],["nat","tan"],["ate","eat","tea"]]

Example 2:

Input: strs = [""]
Output: [[""]]

Example 3:

Input: strs = ["a"]
Output: [["a"]]

Constraints:

• 1 <= strs.length <= 104
• 0 <= strs[i].length <= 100
• strs[i] consists of lower-case English letters.

[Java]

1. Think: if string length is different they could not be in the same list, we can sort the char as a key. Create a hashmap to store same result.
2. add them into a List<List<String>>
3. hard part is to convert stirng to char Array, char Array back to string, put string into a List, and result a series of List.