排序算法——快速排序(Quick Sort)

快速排序（一）

一次划分；递归算法 

C/C++代码：

#include <iostream>
#include <stdlib.h>

using namespace std;

void Print( int r[], int n )
{
	for( int i = 0; i < n; i++ )
	{
		cout << r[i] << "  ";
	}
	cout << endl;
}

void Swap( int& a, int & b )
{
	int temp = a;
	a = b;
	b = temp;
}

int Partition( int r[], int left, int right )
{
	int i = left, j = right;
	while ( i < j )
	{
		while( i < j && r[i] <= r[j] ) j--;
		if( i < j ) { Swap( r[i], r[j] ); i++; }
		
		while( i < j && r[i] <= r[j] ) i++;
		if( i < j ) { Swap( r[i], r[j] ); j--; }	
	}
	return i;
}

void QuickSort( int r[], int left, int right )
{
	if( left < right )
	{
		int pivot = Partition( r, left, right );
		QuickSort( r, left, pivot-1 );
		QuickSort( r, pivot+1, right );
	}
	return;
}


int main()
{
	int r[] = { 34, 12, 45, 78, 52, 18, 67, 90, 64, 72, 27 };
	int n = sizeof( r ) / sizeof( int );
	Print( r, n );
	QuickSort( r, 0, n - 1 );
	Print( r, n );
	
	system( "PAUSE" );
	
	return 0;
}