1436_Destination City

/*  1436_Destination City
Runtime: 1 ms, faster than 100.00% of Java online submissions for Destination City.
Memory Usage: 39.1 MB, less than 75.02% of Java online submissions for Destination City.
*/


class Solution {
    public String destCity(List<List<String>> paths) {
      if(paths==null || paths.size()==0)
          return "";

        HashMap<String, String> map = new HashMap<>();
        
        for(List<String> path : paths)
        {
            map.put(path.get(0), path.get(1));
        }
        
        for(String city : map.values())
        {
            if(!map.containsKey(city)) {
                return city;
            }
        }
        
        return "";
    }
}