思路：主要還是采用分治思想，對(duì)于每一小塊，設(shè)置“信標(biāo)”，將小于信標(biāo)的放在左邊，將大于信標(biāo)的放在右邊

int partition(vector<int>& arr, int l, int r)

{

????int flag = arr[r];

????int x = l;

????for (int j = l; j < r; j++)

????{

????????if (arr[j] < flag)

????????{

????????????swap(arr[j], arr[x]);

????????????x++;

????????}

????}

????swap(arr[x], arr[r]);

????return x;

}

void quikeSort(vector<int>& arr, int l,int r)

{

????if (l < r)

????{

????????int q= partition(arr, l, r);

????????quikeSort(arr, l, q - 1);

????????quikeSort(arr, q + 1, r);

????}

}