剑指 Offer 45. 把数组排成最小的数

public static String minNumber(int[] nums) {

            //to IntStream
    return Arrays.stream(nums)
            //to Stream<Integer>
            .boxed()
            //Stream<String>
            .map(String::valueOf)
            //排序
            .sorted((o1, o2) -> (o1 + o2).compareTo(o2 + o1))
            //to String
            .collect(Collectors.joining(""));

}