#include<iostream>
using namespace std;

// 交換兩個數(shù)
void swap(int &i, int &j)
{
    int t = i;
    i = j;
    j = t;
}

// 打印數(shù)組
void show(int a[], int n)
{
    for(int i = 0; i < n; i++)
    {
        cout << a[i] << " ";
    }
    cout << endl;
}

// 雙向起泡排序
void bubblesort(int a[], int n)
{
    int low = 0, high = n-1;
    bool flag = true;

    while(low < high && flag)
    {   
        flag = false;

        show(a, 10);
        int i = low;
        while(i < high)
        {
            if(a[i] > a[i + 1])
            {
                swap(a[i], a[i + 1]);
                flag = true;
            }
            i++;
        }
        high--;
        
        int j = high;
        while(j > low)
        {
            if(a[j] < a[j-1])
            {
                swap(a[j-1], a[j]);
                flag = true;
            }
            j--;
        }
        low++;
    }
}

int main(){
    int a[] = {10, 9, 8, 7, 6, 5, 4, 3, 2, 1};
    int n = 10;

    // 輸出初始狀態(tài)
    // show(a, n);

    // 雙向冒泡排序
    bubblesort(a, n);

    // 排序后輸出
    cout << "after sort" << endl;
    show(a, n);

}