1038 Recover the Smallest Number (30)

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.

Sample Input:

5 32 321 3214 0229 87

Sample Output:

22932132143287

 单独考虑组合为0的情况

#include<iostream>
#include<algorithm>
#include<vector>
#include<string>
using namespace std;
bool cmp(string a, string b){return a+b<b+a;}
int main(){
  int n, i;
  vector<string> v;
  string ans="";
  cin>>n;
  v.resize(n);
  for(i=0; i<n; i++) cin>>v[i];
  sort(v.begin(), v.begin()+n, cmp);
  for(i=0; i<n; i++) ans+=v[i];
  for(i=0; i<ans.size(); i++)if(ans[i]!='0')break;
  if(i==ans.size()) cout<<"0";
  for(; i<ans.size(); i++) cout<<ans[i];
  return 0;
}