Largest Number

Given a list of non negative integers, arrange them such that they form the largest number.

Example 1:

Input: [10,2]
Output: "210"

Example 2:

Input: [3,30,34,5,9]
Output: "9534330"

Note: The result may be very large, so you need to return a string instead of an integer.

Solution:

class Solution {
    public String largestNumber(int[] nums) {
        List<String> strs = new ArrayList();
        for (int n : nums) {
            strs.add(Integer.toString(n));
        }
        Collections.sort(strs, (a, b) -> {
            String aB = a + b;
            String bA = b + a;
            return bA.compareTo(aB);
        });
        StringBuilder sb = new StringBuilder();
        for (String s : strs) {
            if (sb.length() > 0 && sb.charAt(0) == '0' && s.equals("0")) {
                continue;
            }
            sb.append(s);
        }
        return sb.toString();
    }
}