快速排序

int Partition(int* arr, int left, int right)

{

int data=arr[left];

while(left<right)

{

while(left<right&&data<=arr[right]) right--;

arr[left]=arr[right];

while(left<right&&data>arr[left]) left++;

arr[right]=arr[left];

}

 

arr[left]=data;

return left;

}

 

void QSort(int* arr, int left, int right)

{

if(left>=right)

return;

 

int mid=Partition(arr,left, right);

QSort(arr, left, mid-1);

QSort(arr, mid+1, right);

}

 

void QuickSort(int* arr, int len)

{

QSort(arr, 0, len-1);

}

快速排序非递归

 int* QuickSortNo(int*arr, size_t n)

        {

if(n<2) return arr;

            

stack<int> s;

            s.push(0);

            s.push(n - 1);

 

            while (s.size())

            {

                int right = s.top();

s.pop();

                int left = s.top();

s.pop();

 

                if (left < right)

                {

                    int mid = Partition(arr, left, right);

                    s.push(left);

                    s.push(mid - 1);

 

                    s.push(mid + 1);

                    s.push(right);

                }

            }

        }