Orig Description
Problem B: Monday-Saturday Prime Factors
Chief Judge's log, stardate 48642.5.
We have decided to make a problem from elementary number theory.
The problem looks like finding all prime factors of a positive integer,
but it is not.
A positive integer whose remainder divided by 7 is either 1 or 6 is called
a 7N+{1,6} number.
But as it is hard to pronounce,
we shall call it a Monday-Saturday number.
For Monday-Saturday numbers a and b,
we say a is a Monday-Saturday divisor of b
if there exists a Monday-Saturday number x
such that ax = b.
It is easy to show that
for any Monday-Saturday numbers a and b,
it holds that a is
a Monday-Saturday divisor of b
if and only if
a is a divisor of b in the usual sense.
We call a Monday-Saturday number a Monday-Saturday prime
if it is greater than 1 and has no Monday-Saturday divisors
other than itself and 1.
A Monday-Saturday number which is a prime in the usual sense
is a Monday-Saturday prime
but the converse does not always hold.
For example, 27 is a Monday-Saturday prime
although it is not a prime in the usual sense.
We call a Monday-Saturday prime
which is a Monday-Saturday divisor of a Monday-Saturday number a
a Monday-Saturday prime factor of a.
For example, 27 is one of the Monday-Saturday prime factors of 216,
since 27 is a Monday-Saturday prime
and 216 = 27 × 8 holds.
Any Monday-Saturday number greater than 1
can be expressed as a product of one or more Monday-Saturday primes.
The expression is not always unique
even if differences in order are ignored.
For example,
216 = 6 × 6 × 6 = 8 × 27
holds.
Our contestants should write a program that outputs
all Monday-Saturday prime factors
of each input Monday-Saturday number.
Input
The input is a sequence of lines each of which contains a single
Monday-Saturday number.
Each Monday-Saturday number is greater than 1
and less than 300000 (three hundred thousand).
The end of the input is indicated by a line
containing a single digit 1.
Output
For each input Monday-Saturday number,
it should be printed, followed by a colon `:'
and the list of its Monday-Saturday prime factors on a single line.
Monday-Saturday prime factors should be listed in ascending order
and each should be preceded by a space.
All the Monday-Saturday prime factors should be printed only once
even if they divide the input Monday-Saturday number more than once.
Sample Input
205920
262144
262200
279936
299998
1
Output for the Sample Input
205920: 6 8 13 15 20 22 55 99
262144: 8
262200: 6 8 15 20 50 57 69 76 92 190 230 475 575 874 2185
279936: 6 8 27
299998: 299998
Extracted Specification
An integer \(N\) (2 ≤ \(N\) < 300000), representing some positive quantity.
A sequence of integers, each greater than 1 and less than 300000, terminated by a single digit 1.
### Example Input:
```
205920
262144
262200
279936
299998
1
```
### Function Signature:
Write a function f(inputs) that takes in the input.
```
def f(inputs: List[int]):
'''
inputs: a list of integers
'''
```
Test Case Generator
Sure, here is a test case generator for the "Monday-Saturday Prime Factors" problem:
```python
import random
def is_monday_saturday_number(n):
return n % 7 == 1 or n % 7 == 6
def generate_monday_saturday_numbers(limit):
monday_saturday_numbers = []
for i in range(2, limit):
if is_monday_saturday_number(i):
monday_saturday_numbers.append(i)
return monday_saturday_numbers
def generate_test_case():
limit = 300000
monday_saturday_numbers = generate_monday_saturday_numbers(limit)
test_cases = []
number_of_cases = random.randint(1, 10)
for _ in range(number_of_cases):
test_case = random.choice(monday_saturday_numbers)
test_cases.append(test_case)
test_cases.append(1) # End of input
return test_cases
# Example of generating a test case
test_cases = generate_test_case()
for tc in test_cases:
print(tc)
```
This script defines several functions:
1. `is_monday_saturday_number` checks if a number is a "Monday-Saturday number".
2. `generate_monday_saturday_numbers` generates all "Monday-Saturday numbers" up to a given limit.
3. `generate_test_case` generates a random list of "Monday-Saturday numbers" and appends a `1` to signify the end of input as per the problem statement.
The generated test cases will be random but constrained within the problem's limits. The script makes sure the "Monday-Saturday numbers" are chosen correctly and the input format follows the given constraints.
Extract Arguments
def extract_arguments(fh):
numbers = []
while True:
line = fh.readline().strip()
if line == '1':
break
numbers.append(int(line))
return numbers
# if __name__ == "__main__":
# input_path = sys.argv[1]
# with open(input_path, 'r') as fh:
# numbers = extract_arguments(fh)
# # Process the numbers as needed