LeetCode題解：Group Anagrams

LeetCode題解：Group Anagrams

Given an array of strings, group anagrams together.

For example, given: [“eat”, “tea”, “tan”, “ate”, “nat”, “bat”],
Return:

[
[“ate”, “eat”,”tea”],
[“nat”,”tan”],
[“bat”]
]
Note:
For the return value, each inner list’s elements must follow the lexicographic order.
All inputs will be in lower-case.

題意：找出給定字符串數組中，能組成不同字母順序的單詞的序列，具體看例子

解決思路：符合題意的字符串只要對字母排序，就會呈現一樣的順序，所以我們只要用HashMap存儲對應的序列和符合要求的字符串就可以

代碼：

public class Solution {
    public List anagrams(String[] strs) {

        Map pairs = new HashMap();
        List result = new LinkedList();
        Map remain = new HashMap();

        for (String s:strs) {
            char[] key = s.toCharArray();
            Arrays.sort(key);
            if (key.length == 0) key = null;
            String k = key != null ? new String(key) : null;
            String pair = pairs.put(k, s);
            if (pair != null) {
                result.add(pair);
                remain.put(k, s);
            }
        }

        result.addAll(remain.values());
        return result;
    }
}