Anagrams

    两个字符串的字符个数完全相同，这两个字符串是Anagrams。因此Anagrams至少指俩字符串。找出字符集合中的Anagrams组。

vector<string> anagrams(vector<string> &strs)
{
    vector<string> ret;
    map<string, vector<const string *> > mapAnagram;

    for (vector<string>::const_iterator it = strs.begin();
        it != strs.end();
        ++it)
    {
        string key(*it);

        sort(key.begin(), key.end());
        mapAnagram[key].push_back(&*it);
    }

    for (map<string, vector<const string *> >::const_iterator it = mapAnagram.begin();
        it != mapAnagram.end();
        ++it)
    {
        if (it->second.size() > 1)
        {
            for (vector<const string *>::const_iterator itstr = it->second.begin();
                itstr != it->second.end();
                ++itstr)
            {
                ret.push_back(**itstr);
            }
        }
    }

    return ret;
}