#include <iostream>
using namespace std;
/* run this program using the console pauser or add your own getch, system("pause") or input loop */

void sort(int a1[],int len, int updown); 
int main(int argc, char** argv) {
	int len = 5;
	int a1[len] = {20, 51, 9, 62, 30};
	cout<<"(before sort) a1 = ";
	for(int i=0;i<len;i++) 
	{
		cout<<a1[i]<<", ";
	}
	cout<<endl;

	// updown = -1：由大到小 
	sort(a1,len,-1);
	
	cout<<"(after sort) a1 = ";
	for(int i=0;i<len;i++) 
	{
		cout<<a1[i]<<", ";
	}
	cout<<endl;
	

	
	return 0;
}

////API: int - sort() /////////////
void sort(int a1[], int len, int updown=1)
{
	//a1：排序的整數陣列
	//len：陣列大小
	//updown = 1：由小到大， updown = -1：由大到小，
	int temp=0;
	bool conds = false;
	for(int i=0;i<=len-1;i++)
	{
		for(int j=i+1;j<=len;j++) 
		{
			if(updown == 1)conds= a1[i]>a1[j];
			if(updown == -1)conds= a1[i]<a1[j];
			if(conds)
			{
				temp = a1[i];
				a1[i] = a1[j];
				a1[j] = temp;
			}
		}
	}	
}