CodeIQ 「進捗ないですマーク」問題の僕の回答

CodeIQ 「進捗ないですマーク」問題の僕の回答です。

Python の皮をかぶった SQL です。

#sinchokuniq

#!/usr/bin/env python
# -*- coding: utf-8 -*-
import sqlite3


def main():
    try:
        conn = sqlite3.connect(':memory:')
        strSQL = '''
SELECT
        'invalid'
    WHERE
        :1 & 1 = 0
UNION ALL
SELECT
    *
FROM
    (
WITH P(x,y) AS (
        WITH X(x) AS (
                SELECT 1 WHERE :1 & 1 = 1
                UNION ALL SELECT x + 1 FROM X WHERE x < :1)
        SELECT X,1 FROM X
        UNION ALL SELECT P.x,P.y + 1 FROM P WHERE y < :1)
    SELECT
        group_concat(
            CASE
                WHEN
                        x = 1
                        or x = :1
                        or x = y
                    THEN 'n'
                ELSE '.'
            END,'')
    FROM P
    GROUP BY y
);
'''
        n = int(input())
        lines = conn.execute(strSQL, (n,)).fetchall()
        for line in lines:
            print(line[0])
    finally:
        conn.close()


if __name__ == '__main__':
    main()