快排

class Solution {
public:
	int Partition(vector<int> &nums, int left, int right)
	{
		// 采用子序列的第一个元素为枢纽元素
		int pviont = nums[left];
		while (left<right)
		{
			// 从后往前在后半部分中寻找第一个小于枢纽元素的元素
			while(nums[right]>pviont)
			{
				right--;
			}
			swap(nums[right], nums[left]);
			while (nums[left]<pviont)
			{
				left++;
			}
			swap(nums[right], nums[left]);
		}
		return left;
	}
	void quickSort(vector<int> &nums,int left,int right)
	{
		if (left<right)
		{
			int n = Partition(nums, left, right);
			quickSort(nums, left, n);
			quickSort(nums, n+1, right);
		}
	}
};