HackerRank Python: Designer Door Mat Solution

Table of Contents

Question

Mr. Vincent works in a door mat manufacturing company. One day, he designed a new door mat with the following specifications:

Mat size must be N X M. (N is an odd natural number, and M is 3 times N.)
The design should have ‘WELCOME’ written in the center.
The design pattern should only use |, . and - characters.

Sample Designs

    Size: 7 x 21 
    ---------.|.---------
    ------.|..|..|.------
    ---.|..|..|..|..|.---
    -------WELCOME-------
    ---.|..|..|..|..|.---
    ------.|..|..|.------
    ---------.|.---------
    
    Size: 11 x 33
    ---------------.|.---------------
    ------------.|..|..|.------------
    ---------.|..|..|..|..|.---------
    ------.|..|..|..|..|..|..|.------
    ---.|..|..|..|..|..|..|..|..|.---
    -------------WELCOME-------------
    ---.|..|..|..|..|..|..|..|..|.---
    ------.|..|..|..|..|..|..|.------
    ---------.|..|..|..|..|.---------
    ------------.|..|..|.------------
    ---------------.|.---------------

Input Format

A single line containing the space separated values of N and M.

Constraints

5 < N < 101
15 < M < 303

Output Format

Output the design pattern.

Sample Input

9 27

Sample Output

------------.|.------------
---------.|..|..|.---------
------.|..|..|..|..|.------
---.|..|..|..|..|..|..|.---
----------WELCOME----------
---.|..|..|..|..|..|..|.---
------.|..|..|..|..|.------
---------.|..|..|.---------
------------.|.------------

Solution

				
					N, M = map(int, input().split())

# Upper Half
for i in range(N//2):
    pattern = ".|." * (2*i + 1)
    print(pattern.center(M, "-"))

# Center Line
print("WELCOME".center(M, "-"))

# Lower Half
for i in range(N//2-1, -1, -1):
    pattern = ".|." * (2*i + 1)
    print(pattern.center(M, "-"))

Explanation

The input values for N and M are read from the user and stored in the variables.
The first loop generates the upper half of the door mat. It iterates from 0 to N//2 (excluding) and prints each line. The line is constructed by creating a pattern with ".|." repeated (2*i + 1) times and centering it within a line of width M filled with “-” characters using the center method.
The “WELCOME” line is printed in the center using the center method.
The second loop generates the lower half of the door mat. It iterates from N//2-1 down to 0 (including) and prints each line. The line is constructed similarly to the upper half.