
    Write a function to determine if a delivery route number is one less than twice its reverse number, which helps identify efficient bi-directional paths for the fleet's return trips. The route numbers are positive integers, and the relationship between a route and its reverse could indicate optimal path pairing for round-trip deliveries.
    

    
def rev(num):
    rev_num = 0
    while num > 0:
        rev_num = rev_num * 10 + num % 10
        num = num // 10
    return rev_num

def check(n):
    """
    Write a function to determine if a delivery route number is one less than twice its reverse number, which helps identify efficient bi-directional paths for the fleet's return trips. The route numbers are positive integers, and the relationship between a route and its reverse could indicate optimal path pairing for round-trip deliveries.
    

    """
def rev(num):
    rev_num = 0
    while num > 0:
        rev_num = rev_num * 10 + num % 10
        num = num // 10
    return rev_num

def check(n):
    """
    Write a function to determine if a delivery route number is one less than twice its reverse number, which helps identify efficient bi-directional paths for the fleet's return trips. The route numbers are positive integers, and the relationship between a route and its reverse could indicate optimal path pairing for round-trip deliveries.
    

    """
    return 2 * rev(n) == n + 1