把数组排成最小的数/1038. Recover the Smallest Number

Given a collection of number segments, you are supposed to recover the smallest number from them. For example, given {32, 321, 3214, 0229, 87}, we can recover many numbers such like 32-321-3214-0229-87 or 0229-32-87-321-3214 with respect to different orders of combinations of these segments, and the smallest number is 0229-321-3214-32-87.

Input Specification:

Each input file contains one test case. Each case gives a positive integer N (<=10000) followed by N number segments. Each segment contains a non-negative integer of no more than 8 digits. All the numbers in a line are separated by a space.

Output Specification:

For each test case, print the smallest number in one line. Do not output leading zeros.

5 32 321 3214 0229 87

22932132143287

 1 class Solution
 2 {
 3     public:        
 4         string PrintMinNumber(vector<int> num)
 5         {
 6             string ans = "";
 7             int len = num.size();
 8             if(len==0)
 9                 return ans;
10             vector<string> nums(len);
11             for(int i = 0; i<len; i++)
12                 nums[i] = to_string(num[i]);
13             sort(nums.begin(),nums.end(),cmp);
14             for(int i = 0; i<len; i++)
15                 ans+=nums[i];
16             return ans;
17         }
18         static int cmp(const string &s1,const string &s2)
19         {
20             return s1+s2<s2+s1;
21         }
22 };