A1038 Recover the Smallest Number (30 point(s))

组成最小数

1. 原文

原题

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 (≤$10^4$) 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. Notice that the first digit must not be zero.

Sample Input:

5 32 321 3214 0229 87

Sample output:

22932132143287

2. 解析

组最小数

bool cmp(string a,string b)
{
	return a+b<b+a;
}

3. AC代码

#include<iostream>
#include<string>
#include<algorithm>
using namespace std;
string str[10010];
bool cmp(string a,string b){
	return a+b<b+a;
}
int main(){
	int n;
	cin>>n;
	for (int i = 0; i < n; ++i)
	{
		cin>>str[i];
	}
	sort(str,str+n,cmp);
	string ans;
	for (int i = 0; i < n; ++i)
	{
		ans+=str[i];
	}
	while(ans.length()-1>0&&ans[0]=='0'){
		ans.erase(ans.begin());
	}
	cout<<ans<<endl;
	return 0;
}