Collecting numbers in ascending order
Here are a few suggestions:


You should get in the habit of wrapping all code that isn't contained in a function, in a main guard. This will protect the code from being run when the file is imported.
Instead of code like, for example, s = "x" + str(i) + "x", you should use f""in front of your strings so you can directly include variable names into the strings, like so: s = f"x{i}x".
You should include module docstrings for all your functions. This will help any documentation identify what your functions are supposed to do.
Running your code through pylint, here are a few warnings:


Parameters: Having one letter parameters isn't a good practice. Your code lit up when I first pasted it into my editor. Having meaningful names for your parameters also helps remind you what your function is supposed to take in.
Spacing: Any spacing like s=1 or a=b+c should be spread out to s = 1 and a = b + c. This improves the readability of your code greatly.



Below is the refactored code:

def swap(array, index_one, index_two):
    """ Swaps two values in an array, then returns the new array"""
    temp = array[index_one]
    array[index_one] = array[index_two]
    array[index_two] = temp
    return array


def is_same_round(tables, element_one, element_two):
    """
    Returns True if the index of `element_one` is greater than the index
    of `element_two`
    """
    return tables.index(element_one) &lt; tables.index(element_two)

def solve(file):
    """ Solves the file """
    tables = [line.strip('\n') for line in open(file)]
    for i in range(len(tables)):
        tables[i] = int(tables[i][0:len(tables[i]) - 1])
    tables = tables[1:len(tables)]
    roundnumbers = []
    for i in range(len(tables)):
        for j in range(i + 1, len(tables)):
            rounds = 1
            tables = swap(tables, i, j)
            for luku in range(1, len(tables)):
                if not is_same_round(tables, luku, luku + 1):
                    rounds += 1
            roundnumbers.append(rounds)
            tables = swap(tables, i, j)

    result = f"{len(tables)} {min(roundnumbers)} {roundnumbers.count(min(roundnumbers))}"
    print(result)

if __name__ == '__main__':
    for i in range(1, 10):
        file_to_solve = f'junar{i}.in'
        solve(file_to_solve)