Problem p01989 - Generation 1

Orig Description

A: IP Address (Internet Protocol Address)
Problem
Given a string of digits, count the number of valid ways to split it into an IPv4 address.
A split is valid if and only if:
The string is split into four parts, each containing one to three digits.
Each part is not empty and represents a number from 0 to 255, inclusive, when interpreted as a decimal number.
If a part is 0, then it must be a single digit, '0'.
If a part is not 0, then it must not start with the digit, '0'.
Input Format
S
Constraints
4 \leq |S| \leq 12
The string, S, consists only of digits.
Output Format
Output the number of valid ways to split the given string into an IPv4 address.
Sample Input 1
123456789
Sample Output 1
1
There is only one valid way to split the given string into an IPv4 address: '123.45.67.89'.
Sample Input 2
768426
Sample Output 2
6

Extracted Specification

Canonicalized Input Description:

A string S of digits with length between 4 and 12, inclusive.

### Example Input:

```
123456789
```

### Function Signature:
Write a function f(S) that takes in the input.
def f(S: str):
    '''
    S: a string of digits
    '''

Test Case Generator

Sure! To generate test cases for the given problem statement, we need to take into account the constraints and the format of the input. Here is a test case generator for the problem of counting valid ways to split a string into an IPv4 address:

```python
import random

def generate_ip_string():
    length = random.randint(4, 12)  # |S| should be between 4 and 12
    S = ''.join(random.choices('0123456789', k=length))
    return S

def tcgen():
    S = generate_ip_string()
    return S

# Example usage
if __name__ == "__main__":
    for _ in range(5):  # Generate 5 test cases
        print(tcgen())
```

This generator function creates a string \( S \) of digits with a length between 4 and 12, which conforms to the constraints provided in the problem statement. This should help generate diverse and random test cases to test the solution's robustness.

Here's a brief explanation of the code:
1. **generate_ip_string()**: This function generates a random string of digits of a length between 4 and 12.
2. **tcgen()**: This function calls `generate_ip_string()` to get the test string \( S \) and returns it.
3. **Example usage**: This section demonstrates how to use the `tcgen()` function to generate multiple test cases. In this example, it generates 5 test cases and prints them.

Extract Arguments

def extract_arguments(fh):
    S = fh.readline().strip()
    return (S,)