public void quickSort(int[] nums,int L,int R){
        if(L>=R){
            return;
        }
        int left=L;
        int right=R;
        int pivot = nums[left];
        while(left<right){
            while(left<right&&nums[right]>pivot){
                right--;
            }
            if(left<right){
                nums[left++]=nums[right];
            }
            while(left<right&&nums[left]<pivot){
                left++;
            }
            if(left<right){
                nums[right--]=nums[left];
            }
        }
        nums[left]=pivot;
        quickSort(nums,L,left-1);
        quickSort(nums,left+1,R);
    }