LeetCode OJ 49. Group Anagrams

题目

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: All inputs will be in lower-case.

解答

作为一个爸爸，就算生病也要更博。

这题很水啊，对每个字符串中的字符做个排序，这样同字母异序词就会变成同字母同序词了，然后用一个map把同字母异序词存储在一个pair下，就OK了。

下面是AC的代码：

class Solution {
public:
    map<string, vector<string>> hashset;
    vector<vector<string>> groupAnagrams(vector<string>& strs) {
        for(vector<string>::iterator iter = strs.begin(); iter != strs.end(); iter++){
            string s = *iter;
            char *temp_str = (char *)(iter->c_str());
            sort(temp_str, temp_str + strlen(temp_str));
            map<string, vector<string>>::iterator temp_iter = hashset.find(string(temp_str));
            if(temp_iter != hashset.end()){
                (temp_iter->second).push_back(s);
            }
            else{
                vector<string> new_vector;
                new_vector.push_back(s);
                hashset.insert(pair<string, vector<string>>(string(temp_str), new_vector));
            }
        }
        vector<vector<string>> ans;
        for(map<string, vector<string>>::iterator iter = hashset.begin(); iter != hashset.end(); iter++){
            ans.push_back(iter->second);
        }
        return ans;
    }
};

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