拼接最小字典序练习题

     public class Mycomparator implements Comparator<String> {
 
        @Override
        public int compare(String a, String b) {
            // TODO Auto-generated method stub
            return (a + b).compareTo(b+a);
        }
 
    }
    public String findSmallest(String[] strs, int n) {
        // write code here
        if(strs == null || n==0){
            return "";
        }
        Arrays.sort(strs, new Mycomparator());
 
        String res = "";
        for (int i = 0; i < n; i++) {
            res += strs[i];
        }
        return res;
    }