Largest Number
<p>Given a list of non-negative integers <code>nums</code>, arrange them such that they form the largest number and return it.</p>

<p>Since the result may be very large, so you need to return a string instead of an integer.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> nums = [10,2]
<strong>Output:</strong> &quot;210&quot;
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> nums = [3,30,34,5,9]
<strong>Output:</strong> &quot;9534330&quot;
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= nums.length &lt;= 100</code></li>
	<li><code>0 &lt;= nums[i] &lt;= 10<sup>9</sup></code></li>
</ul>
Greedy; Array; String; Sorting
class Solution {
public:
    string largestNumber(vector<int>& nums) {
        vector<string> vs;
        for (int v : nums) vs.push_back(to_string(v));
        sort(vs.begin(), vs.end(), [](string& a, string& b) {
            return a + b > b + a;
        });
        if (vs[0] == "0") return "0";
        string ans;
        for (string v : vs) ans += v;
        return ans;
    }
};