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
题目大意：
从给定数字中进行排序，找到排序后序列最小的一个并输出。
这是一个贪心算法类问题，最简单的排序算法就是直接用sort，cmp函数定义为将两个字符串分别正着拼接和反着拼接，比较大小。
代码如下：
#include <iostream>
#include <algorithm>
#include <cstdio>
#include <string>
#include <vector>
using namespace std;
bool cmp(string a, string b){
return a + b < b + a;
}
int main(){
int n;
cin >> n;
vector<string> L(n);
for(int i = 0; i < n; i++)
cin >> L[i];
sort(L.begin(), L.end(), cmp);
string output;
for(int i = 0; i < L.size(); i++){
output += L[i];
}
int it;
for(it = 0; output[it] == '0'; it++);
if(it != output.size())
for(; it < output.size(); it++)
cout << output[it];
else cout << 0;
return 0;
}