解题思路：

贪心

class Solution {
    public String crackPassword(int[] password) {
        String[] strs = new String[password.length];
        for(int i = 0; i < password.length; i++)
            strs[i] = String.valueOf(password[i]);
        Arrays.sort(strs, (x, y) -> (x + y).compareTo(y + x));
        StringBuilder res = new StringBuilder();
        for(String s : strs)
            res.append(s);
        return res.toString();
    }
}