Problem p02113 - Generation 2

Orig Description

Problem C: Palindrome
Problem
Taro has N strings of length L each. He loves palindromes, so he wants to choose some of the N strings, arrange them in any order he likes, and make the longest palindrome possible.
Find the longest palindrome that Taro can make. If there are multiple palindromes of the same length, output the lexicographically smallest one. If it is impossible to make a palindrome no matter how he chooses and arranges strings, output an empty line.
Input
The input is given in the following format:
N L
s1
s2
.
.
.
sN
The first line contains two integers N and L which are the number of strings and the length of the strings, respectively. The following N lines contain the strings that Taro has.
Constraints
The input satisfies the following constraints:
1 ≤ N ≤ 1000
1 ≤ L ≤ 30
si consists of lowercase English letters.
Output
Output the lexicographically smallest longest palindrome that can be made. If it is impossible to make a palindrome, output an empty line.
Sample Input 1
4 2
oi
io
rr
rr
Sample Output 1
iorrrroi
Sample Input 2
5 1
a
b
c
a
c
Sample Output 2
acbca
Sample Input 3
3 3
uki
uku
uke
Sample Output 3
uku

Extracted Specification

An integer N (1 ≤ N ≤ 1000), representing some quantity or size.
An integer L (1 ≤ L ≤ 30), representing some other quantity or size.
N strings of length L, each consisting of lowercase English letters.

### Example Input:

```
4 2
oi
io
rr
rr
```

### Function Signature:
Write a function f(N, L, strings) that takes in the input.
```python
def f(N: int, L: int, strings: List[str]):
    '''
    N: an integer
    L: an integer
    strings: a list of strings
    '''
```

Test Case Generator

Certainly! Let's create a test case generator for the given problem "Palindrome".

The goal is to generate random test cases that adhere to the problem constraints and format. 

Here is the implementation of the test case generator:

```python
import random
import string

def generate_random_string(length):
    return ''.join(random.choices(string.ascii_lowercase, k=length))

def tcgen():
    # Number of strings, 1 ≤ N ≤ 1000
    N = random.randint(1, 1000)
    
    # Length of each string, 1 ≤ L ≤ 30
    L = random.randint(1, 30)
    
    # Generate N strings of length L
    strings = [generate_random_string(L) for _ in range(N)]
    
    return N, L, strings

# Example usage of the generator
N, L, strings = tcgen()
print(N)
print(L)
for s in strings:
    print(s)
```

This code will create a valid random test case for the problem statement. It:

1. Generates a random integer `N` between 1 and 1000.
2. Generates a random integer `L` between 1 and 30.
3. Creates `N` strings each of length `L` consisting of lowercase English letters.

You can run this script to generate random test cases and use them to test the solution for the problem "Palindrome".

Extract Arguments

def extract_arguments(fh):
    N, L = map(int, fh.readline().strip().split())
    strings = [fh.readline().strip() for _ in range(N)]
    return N, L, strings