Given an array of strings, group anagrams together.
Example:
Input: ["eat", "tea", "tan", "ate", "nat", "bat"]
,
Output:
[
["ate","eat","tea"],
["nat","tan"],
["bat"]
]
/* 把字母构成(包括次数)相同的单词放在一起
* 最简单的方法: asdf fdsa dfas 按字母排序后都是asdf
*
* 关键是设立一种映射方法: hash(asdf)=hash(fdsa)=hash(dfas)
* 统计出现次数 合成字符串?
* 1a2b ?
*
* 其实二者效率差不多
* */
class Solution {
public:
vector<vector<string>> groupAnagrams(vector<string>& strs) {
vector<vector<string>> ret;
unordered_map<string, vector<string>> m;
for(string str:strs){
string tmp(str);
sort(tmp.begin(), tmp.end());
m[tmp].push_back(str);
}
for(auto elem : m)
ret.push_back(elem.second);
return ret;
}
};