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

代码如下：

这次让我加深了对algorithm中的sort有了更深的理解，本来觉得已经会用了，但是今天然我发现还是对它所用的场景有很多欠缺点

#include<iostream>
#include<string>
#include<vector>
#include<algorithm>

using namespace std;

bool less_than(string s1,string s2){
	return s1+s2<s2+s1;
}

int main(){
	int n;
	scanf("%d",&n);
	vector<string> vec;
	string value;
	string final="";
	for(int i=0;i<n;++i){
		cin>>value;
		vec.push_back(value);
	}
	sort(vec.begin(),vec.end(),less_than);
	for(int i=0;i<vec.size();++i){
		final+=vec[i];
	}
	while(final.size()!=0&&final[0]=='0'){
		final.erase(final.begin());
	}
	if(final.size()==0){
		cout<<0;
	}else{
		cout<<final;
	}
	return 0;
}

参照了1038. Recover the Smallest Number (30)-PAT甲级真题（贪心算法）