Anagrams

Q:

Given an array of strings, return all groups of strings that are anagrams.

Note: All inputs will be in lower-case.

A: 重点是理解变位词的概念及其给所有词打tag：字典序

    vector<string> anagrams(vector<string> &strs) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        vector<string> res;
        
        if(strs.empty())
            return res;
            
        map<string,vector<string>> dict;
        
        for(int i=0;i<strs.size();i++)
        {
            string key = strs[i];
            sort(key.begin(),key.end());
            dict[key].push_back(strs[i]);
        }
        
        map<string,vector<string>>::iterator it;
        
        for(it = dict.begin();it!=dict.end();it++)
        {
            if(it->second.size()>1)
            {
                vector<string>::iterator vt;
                for(vt=it->second.begin();vt!=it->second.end();vt++)
                    res.push_back(*vt);
            }
        }
        
        return res;
        
    }