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;
}
};