PAT 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.

Sample Input:

5 32 321 3214 0229 87

Sample Output:

22932132143287

分析
这题的排序和s1,s2的先后位置有关，蛮好玩的,不多说，上代码就知道了

#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;
bool cmp(const string& s1,const string& s2){
    return s1+s2<s2+s1;
}
int main(){
    int n;
    cin>>n;
    vector<string> vi(n);
    for(int i=0;i<n;i++)
        cin>>vi[i];
    sort(vi.begin(),vi.end(),cmp);
    string s="";
    for(auto o:vi)
        s+=o;
    int j=0;
    for(;j<s.size();j++)
        if(s[j]!='0') break;
    if(j==s.size()) cout<<0;
    else
    for(;j<s.size();j++)
        cout<<s[j];
    return 0;
}