code: func Longest(strs []string) string {
  	if len(strs) == 0 {
  		return ""
  	}
  
  	var longest string
  	var llen int
  	for _, str := range strs {
  		if len(str) >= llen {
  			longest = str
  			llen = len(longest)
  		}
  	}
  
  	return longest
  }
docs: // Longest returns the longest element in the string slice in O(n) time and O(1)
  // space. If strs is empty or nil, an empty string will be returned.