Given a list of non negative integers, arrange them such that they form the largest number.For example, given [3, 30, 34, 5, 9], the largest formed number is 9534330.Note: The result may be very large, so you need to return a string instead of an integer.

class Solution {public:    string largestNumber(vector<int>& nums) {        string restr = "";        sort(nums.begin(), nums.end(), compare);        for (int i = 0; i < nums.size(); ++i){            restr += to_string(nums[i]);        }        if (restr[0] == ‘0‘){            return "0";        }        return restr;    }        static bool compare(int a, int b){        string stra = to_string(a);        string strb = to_string(b);                return stra + strb > strb + stra;    }};