剑指offer33——把数组排成最小的数

思路：数字转字符串，字符串比较的规则是，两个字符串合并成一个，ab 和 ba，比较两个字符串

static String getMinNum(int[] data) {
   String[] list = new String[data.length];
    for (int i = 0; i < data.length; i++) {
        list[i] = Integer.toString(data[i]);
    }
    Arrays.sort(list,((o1, o2) -> {
        String str1 = o1+o2;
        String str2 = o2+o1;
        return str1.compareTo(str2);
    }));
    StringBuilder sb = new StringBuilder();
    for (String s : list) {
        sb.append(s);
    }
    return sb.toString();
}
public static void main(String[] args) {
    int[] num = {3,32,33};
    System.out.println(getMinNum(num));
}