1038. Recover the Smallest Number (30)

题目链接：https://www.patest.cn/contests/pat-a-practise/1038
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

#include<cstdio>#include<iostream>#include<string>#include<cstring>#include<algorithm>using namespace std;const int maxn=10010;string seg[maxn];bool cmp(string a,string b){    return a+b<b+a;//如{"321","32"},"32"<"321",但32321>32132,因此不能直接return a<b,应该return a+b<b+a;   }int main(){    int n;    scanf("%d",&n);    for(int i=0;i<n;i++){        cin>>seg[i];    }    sort(seg,seg+n,cmp);    string ans;    for(int i=0;i<n;i++){        ans+=seg[i];    }    while(ans.size()!=0&&ans[0]=='0'){        ans.erase((ans.begin()));    }    if(ans.size()==0) cout<<0;    else cout<<ans;    return 0;}