def SUM(arr,start,end): if start==end: return arr[end] else: return arr[start]+SUM(arr,start+1,end)date=[x for x in range(1,10)]print(date)a=SUM(date,0,len(date)-1)print(a)def COUNT(arr,start,end): if start==end: return 1 return 1+COUNT(arr,start+1,end)print(COUNT(date,0,len(date)-1))def findMax(arr,start,end): if start==end: return arr[start] if arr[start]<findMax(arr,start+1,end): return findMax(arr,start+1,end) else: return arr[start]print(findMax(date,0,len(date)-1))def quick_sort(arr): if len(arr)<2: return arr else: pivot=arr[0] less=[i for i in arr[1:] if i<=pivot] larger=[i for i in arr[1:] if i>pivot] return quick_sort(less)+[pivot]+quick_sort(larger)data=[2,3,1,4,7,6]print(quick_sort(data))a=[2,1]a.remove(1)print(a)