1 class Solution {
 2 public:
 3     string minNumber(vector<int>& nums) {
 4         vector<string> vs;
 5         for(int i = 0; i < nums.size(); ++i) 
 6             vs.push_back(to_string(nums[i]));
 7         sort(vs.begin(), vs.end(), cmp);
 8         
 9         string res;
10         for(string &s : vs)
11             res += s;
12 
13         return res;
14     }
15 
16     static bool cmp(string x, string y) {
17         return x + y < y + x;
18     }
19 };