将英文句子的单词拆分，并按按字典顺序排序逐个输出单词

#include<iostream>
#include<string>
#include<vector>
using namespace std;
vector<string> Split(string s,string pattern)
{
	string::size_type pos;
	vector<string> result;
	s += pattern;
	for (int i = 0; i < s.size(); i++)
	{
		pos = s.find(pattern, i);
		if (pos < s.size())
		{
			result.push_back(s.substr(i, pos - i));
			i = pos + pattern.size() - 1;
		}
		
	}
	return result;
}
int Compare(string s1, string s2)
{
	string::size_type s1_len = s1.size();
	string::size_type s2_len = s2.size();
	int i = 0;
	while (i < s1_len && i < s2_len)
	{
		if (s1[i] < s2[i])
		{
			return -1;
		}
		else if (s1[i]>s2[i])
		{
			return 1;
		}
		i++;
	}
	if (i < s1_len)
		return 1;
	if (i < s2_len)
		return -1;
	return 0;
}
void QuickSort(vector<string> &s, int p, int r)
{
	if (p<r)
	{
		int i = p ;
		int j = r;
		string x = s[p];
		while (i<j)
		{
			while (i < j && Compare(s[j], x) == 1)
				j--;
			if (i < j)
				s[i++] = s[j];
			while (i < j && Compare(s[i], x) == -1)
				i++;
			if (i < j)
				s[j--] = s[i];
		}
		s[i] = x;
		QuickSort(s, p, i - 1);
		QuickSort(s, i + 1, r);
	}
}

void Print(string s)
{
	vector<string> vstr;
	vstr = Split(s, " ");
	QuickSort(vstr, 0, vstr.size() - 1);
	for (int i = 0; i < vstr.size(); i++)
		cout << vstr[i] << ' ';
	cout << endl;
}
int main()
{
	string str = "what are you doing";
	string str2 = "i am a student";
	
	Print(str);
	Print(str2);
	return 0;
}