func groupAnagrams(strs []string) [][]string {
mp:=map[string][]string{}
for _,item:=range strs{
s:=[]byte(item)
sort.Slice(s,func(i,j int)bool{return s[i]>s[j]})
sStr:=string(s)
mp[sStr]=append(mp[sStr],item)
}
res:=make([][]string,0,len(mp))
for _,item:=range mp{
res=append(res,item)
}
return res
}