Python program to reverse an array up to a given position

Here given user input array and the position of the array to be reverse.so our task is to reverse this array. We just reverse the sub array from [0 to (n-1)].

Example

Input : A=[3, 7, 6, 4, 1, 2]
n=4
Output : [1, 4, 6, 7, 3, 2]

Algorithm

Step 1: reverse list starting from n-1 position.
Step 2: split remaining list after n.
Step 3: concat both parts and prints

Example code

#Program to reverse an array
#up to a n position

def arrayreverse(A, n):
   #generate list starting from n-1 position element till first element in #reverse order
   print ("REVERSE OF AN ARRAY UPTO",n,"POSITION",A[n-1::-1] + A[n:])

   # Driver program
   if __name__ == "__main__":
      A=list()
      n1=int(input("Enter the size of the List ::"))
      print("Enter the Element of List ::")
      for i in range(int(n1)):
      k=int(input(""))
      A.append(k)
      n=int(input("Enter the position to be reverse ::"))
arrayreverse(A, n)

Output

Enter the size of the List :: 6
Enter the Element of List ::
2
3
4
1
78
23
Enter the position to be reverse : 5
REVERSE OF AN ARRAY UPTO 5 POSITION [78, 1, 4, 3, 2, 23]