Reverse Linked List

class ListNode():
    def __init__(self, val=0, next=None):
        self.val = val
        self.next = next

class Solution():
    def reverseInBetween(self, head, left, right):
        prevLeft, Left = None, head
        for i in range(left-1):
            prevLeft = Left
            Left = Left.next

        curr, prev = Left.next, Left
        for i in range(right-left):
            temp = curr.next
            curr.next = prev
            prev = curr
            curr = temp

        if prevLeft == None:
            head = prev
        else:
            prevLeft.next = prev
        Left.next = curr

        return head


#arr = [1, 2, 3, 4]
#arr = [1, 2,3, 4, 5]
arr = [5]
left, right = 1,1
head = temp = ListNode(arr[0])

for i in arr[1:]:
    temp.next = ListNode(i)
    temp = temp.next

obj = Solution()
head = obj.reverseInBetween(head, left, right)

curr = head
while(curr != None):
    print(curr.val)
    curr = curr.next