HackerRank Alphabet Rangoli problem solution in python | python problem solution

You are given an integer, . Your task is to print an alphabet rangoli of size . (Rangoli is a form of Indian folk art based on creation of patterns.)

Different sizes of alphabet rangoli are shown below:

#size 3

----c----
--c-b-c--
c-b-a-b-c
--c-b-c--
----c----

#size 5

--------e--------
------e-d-e------
----e-d-c-d-e----
--e-d-c-b-c-d-e--
e-d-c-b-a-b-c-d-e
--e-d-c-b-c-d-e--
----e-d-c-d-e----
------e-d-e------
--------e--------

#size 10

------------------j------------------
----------------j-i-j----------------
--------------j-i-h-i-j--------------
------------j-i-h-g-h-i-j------------
----------j-i-h-g-f-g-h-i-j----------
--------j-i-h-g-f-e-f-g-h-i-j--------
------j-i-h-g-f-e-d-e-f-g-h-i-j------
----j-i-h-g-f-e-d-c-d-e-f-g-h-i-j----
--j-i-h-g-f-e-d-c-b-c-d-e-f-g-h-i-j--
j-i-h-g-f-e-d-c-b-a-b-c-d-e-f-g-h-i-j
--j-i-h-g-f-e-d-c-b-c-d-e-f-g-h-i-j--
----j-i-h-g-f-e-d-c-d-e-f-g-h-i-j----
------j-i-h-g-f-e-d-e-f-g-h-i-j------
--------j-i-h-g-f-e-f-g-h-i-j--------
----------j-i-h-g-f-g-h-i-j----------
------------j-i-h-g-h-i-j------------
--------------j-i-h-i-j--------------
----------------j-i-j----------------
------------------j------------------

The center of the rangoli has the first alphabet letter a, and the boundary has the  alphabet letter (in alphabetical order).

Function Description

Complete the rangoli function in the editor below.

rangoli has the following parameters:

• int size: the size of the rangoli

Returns

• string: a single string made up of each of the lines of the rangoli separated by a newline character (n)

Only one line of input containing , the size of the rangoli.

5

--------e--------
------e-d-e------
----e-d-c-d-e----
--e-d-c-b-c-d-e--
e-d-c-b-a-b-c-d-e
--e-d-c-b-c-d-e--
----e-d-c-d-e----
------e-d-e------
--------e--------

Problem solution in Python 2 programming.
from copy import deepcopy
N = int(raw_input())
row = 2 * (N - 1) + 1
col = (N - 1) * 4 + 1
arr = ['-'] * col
res = []
for _ in xrange(row): res.append(deepcopy(arr))
mr = row / 2
mc = col / 2
for i in xrange(mr + 1):
    ch = ord('a') + i
    for j in xrange(N - i):
        res[mr - i][mc - 2 * j] = chr(ch + j)
        res[mr - i][mc + 2 * j] = chr(ch + j)
        res[mr + i][mc - 2 * j] = chr(ch + j)
        res[mr + i][mc + 2 * j] = chr(ch + j)
for r in res:
    print ''.join(r)

Problem solution in Python 3 programming.
def print_rangoli(size):
    alpha = "abcdefghijklmnopqrstuvwxyz"
    data = [alpha[i] for i in range(n)]
    items = list(range(n))
    items = items[:-1]+items[::-1]
    for i in items:
        temp = data[-(i+1):]
        row = temp[::-1]+temp[1:]
        print("-".join(row).center(n*4-3, "-"))

Problem solution in pypy programming.
import string
def print_rangoli(size):
    alpha = string.ascii_lowercase
    n = size
    L = []
    for i in range(n):
        s = "-".join(alpha[i:n])
        L.append((s[::-1]+s[1:]).center(4*n-3, "-"))
    print('n'.join(L[:0:-1]+L))

Problem solution in pypy3 programming.
import string
alpha = string.ascii_lowercase

n = int(input())
L = []
for i in range(n):
    s = "-".join(alpha[i:n])
    L.append((s[::-1]+s[1:]).center(4*n-3, "-"))
print('n'.join(L[:0:-1]+L))