49. Group Anagrams

class Solution {
public:
    vector<vector<string>> groupAnagrams(vector<string>& strs) {
        map<string,int> mp;
        vector<vector<string>> ans;
        int n=strs.size();
        int i,j;
        for(i=0;i<n;i++)
        {
            int tmp[26]={0};
            for(j=0;j<strs[i].size();j++)
            {
                tmp[strs[i][j]-'a']++;      //也可以先按字典序排序
            }
            string s="";
            for(j=25;j>=0;j--)
                s+=tmp[j];
            if(mp.find(s)==mp.end())
            {
                mp[s]=ans.size();
                vector<string> vt{strs[i]};
                ans.push_back(vt);
            }
            else
            {
                ans[mp[s]].push_back(strs[i]);
            }
        }
        return ans;
    }
};