1.递归实现

1.1C语言

#include <stdio.h>

void swap(int v[], int left, int right)
{
	int temp = v[left];
	v[left] = v[right];
	v[right] = temp;

}

void qsort(int v[], int left, int right)
{
	int i, last;
	//void swap(int v[], int i, int j);
	if (left >= right)
		return;
	swap(v, left, (left + right) / 2);
	last = left;
	for (i = left + 1; i <= right; i++)
		if (v[i]<v[left])
			swap(v, ++last, i);
	swap(v, left, last);
	qsort(v, left, last - 1);
	qsort(v, last + 1, right);

}
void quick2Sort(int v[], int left, int right)
{
	//void swap(int v[], int left, int right);
	int i, last;
	if (left >= right)
		return ;
	swap(v, left, (left + right) / 2);
	last = left;
	for (i = left+1; i <= right; i++)
		if (v[i] < v[left])
			swap(v, ++last,i );
	swap(v, left, last);
	quick2Sort(v,left,last-1);
	quick2Sort(v, last + 1,right);

}
int main()
{
	//void swap(int v[], int left, int right);
	//void quickSort(int v[], int left, int right);
	int count2;
	int n = 0;
	int v[4];
	int i = 0;
	int v2[6] = { 9,8,7,6,5,3 };
	int count = 0;
	printf("Hello World!\n");
	while (1)
	{
		scanf("%d", &v[i++]);
		if (getchar() == '\n')
			break;
	}
	printf("you have input:%d\n",i);
	count = i;
	count2 = i - 1;
	for (i = 0; i < 6; i++)
		printf("%d  ", v2[i]);
	quick2Sort(v2, 0, 5);
	//qsort(v2, 0, 5);
	
	for (i = 0; i < 6; i++)
		printf("%d  ", v2[i]);
	//scanf("%d", &n);
	//printf("%d\n", n);

	return 0;
}

1.2 C++实现

#include <iostream>
#include <vector>
//#include <functional>
#include <sstream>
#include <string>
#include <algorithm>
using namespace std;

void  swap(vector<int>&  v,int left,int right)
{
	int temp =v[left];
	v[left] = v[right];
	v[right] = temp;
}

void quick_Sort(vector<int>& v,int left,int right)
{
	int i, last;
	if (left >= right)
		return;
	swap(v, left, (left + right) / 2);
	last = left;
	for (i = left; i <= right; i++)
		if (v[i] < v[left])
			swap(v,++last,i);
	swap(v, left, last);
	quick_Sort(v,left,last-1);
	quick_Sort(v,last+1,right);
	//printf("in\n");
}
vector<int> stringToIntegerVector(string input) {
	vector<int> output;
	//trimLeftTrailingSpaces(input);
	//trimRightTrailingSpaces(input);
	//input = input.substr(1, input.length() - 2);
	stringstream ss;
	ss.str(input);
	string item;
	char delim = ' ';
	while (getline(ss, item, delim)) {
		output.push_back(stoi(item));
	}
	return output;
}

int main()
{
	int n = 0;
	printf("Hello World! 12\n");
	string line;
	getline(cin,line);
	vector<int>  v = stringToIntegerVector(line);
	for (auto i : v) {
		printf(" %d ",i);
	}
	printf("\n");
	quick_Sort(v, 0, v.size() - 1);
	//sort(v.begin(), v.end());
	for (auto i : v) {
		printf(" %d ", i);
	}
	printf("\n");
	//scanf("%d",&n);
	//printf("%d\n",n);
	
	return 0;
}