Group Anagrams
Total Accepted: 76941 Total
Submissions: 275801 Difficulty: Medium
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.
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Hash Table String
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(E) Valid Anagram (E)
Group Shifted Strings
思路：
使用先将字符串数组排序（这样可以保证输出的顺序）；
使用HashMap<String, List<String>>，key(String)：是第1次出现的字符串；value(List<String>)：用于保存所有相同字母乱序的值。
java code:
public class Solution {
public List<List<String>> groupAnagrams(String[] strs) {
if(strs==null || strs.length==0) return new ArrayList<List<String>>();
Map<String, List<String>> map = new HashMap<String, List<String>>();
Arrays.sort(strs);
for(String str : strs) {
char[] cs = str.toCharArray();
Arrays.sort(cs);
String keyStr = new String(cs);
if(!map.containsKey(keyStr)) map.put(keyStr, new ArrayList<String>());
map.get(keyStr).add(str);
}
return new ArrayList<List<String>>(map.values());
}
}