Check Undulating Number

An **undulating number** is a number that alternates between two digits, starting with one digit and then switching to another, and repeating this pattern. For example, `1212121` is undulating, but `1991` is not.

Write a function `is_undulating(n)` that checks whether a given number `n` is undulating or not. The function should return `True` if the number is undulating, and `False` otherwise.

#### Examples
```python [main.nopy]
is_undulating(1212121)  # True
is_undulating(1991)     # False
is_undulating(121)      # True
is_undulating(1)        # False
```

#### Constraints
- The input `n` will be a positive integer.
- A number with fewer than three digits cannot be undulating.

def is_undulating(n):
    """
    Check if the given number is undulating.

    Args:
        n (int): The number to check.

    Returns:
        bool: True if the number is undulating, False otherwise.
    """
    # Convert the number to a string for easier manipulation
    n = str(n)
    # Implement the logic to check for undulating pattern
    pass

Press Shift+Enter or click Run to execute.

Intermediate

More challenges to try

Next Bigger Number Check if String is Integer Check String Start and End Check Monotonic Array Check Pattern Sequence Decimal to Binary Conversion Check Empty Dictionaries Count True Booleans Check No Profit No Loss Largest Number from Digits