Largest Number

class Solution {public:    string largestNumber(vector<int>& nums)     {        string m_res = "";        if (nums.size() < 1)            return m_res;        sort(nums.begin(),nums.end(),compare);                if (nums[0] == 0)            return "0";        for (int i = 0; i < nums.size(); i++)            m_res += to_string(nums[i]);                return m_res;    }        static bool compare(int num1,int num2)    {        string s1 = to_string(num1);        string s2 = to_string(num2);        return s1+s2 > s2+s1;    }    };