python-algorithms/algorithms/strings/text_justification.py at master · ilyvsc/python-algorithms · GitHub

History

89 lines (82 loc) · 3.22 KB

Raw

"""

Given an array of words and a width maxWidth, format the text such that each line

has exactly maxWidth characters and is fully (left and right) justified.

You should pack your words in a greedy approach; that is, pack as many words as

you can in each line. Pad extra spaces ' ' when necessary so that each line has

exactly maxWidth characters.

Extra spaces between words should be distributed as evenly as possible. If the

number of spaces on a line do not divide evenly between words, the empty slots

on the left will be assigned more spaces than the slots on the right.

For the last line of text, it should be left justified and no extra space is

inserted between words.

Note:

A word is defined as a character sequence consisting of non-space characters only.

Each word's length is guaranteed to be greater than 0 and not exceed maxWidth.

The input array words contains at least one word.

Example:

Input:

words = ["What","must","be","acknowledgment","shall","be"]

maxWidth = 16

Output:

[

"What must be",

"acknowledgment ",

"shall be "

]

"""

def text_justification(words, max_width):

'''

:type words: list

:type max_width: int

:rtype: list

'''

ret = [] # return value

row_len = 0 # current length of strs in a row

row_words = [] # current words in a row

index = 0 # the index of current word in words

is_first_word = True # is current word the first in a row

while index < len(words):

while row_len <= max_width and index < len(words):

if len(words[index]) > max_width:

raise ValueError("there exists word whose length is larger than max_width")

tmp = row_len

row_words.append(words[index])

tmp += len(words[index])

if not is_first_word:

tmp += 1 # except for the first word, each word should have at least a ' ' before it.

if tmp > max_width:

row_words.pop()

break

row_len = tmp

index += 1

is_first_word = False

# here we have already got a row of str , then we should supplement enough ' ' to make sure the length is max_width.

row = ""

# if the row is the last

if index == len(words):

for word in row_words:

row += (word + ' ')

row = row[:-1]

row += ' ' * (max_width - len(row))

# not the last row and more than one word

elif len(row_words) != 1:

space_num = max_width - row_len

space_num_of_each_interval = space_num // (len(row_words) - 1)

space_num_rest = space_num - space_num_of_each_interval * (len(row_words) - 1)

for j in range(len(row_words)):

row += row_words[j]

if j != len(row_words) - 1:

row += ' ' * (1 + space_num_of_each_interval)

if space_num_rest > 0:

row += ' '

space_num_rest -= 1

# row with only one word

else:

row += row_words[0]

row += ' ' * (max_width - len(row))

ret.append(row)

# after a row , reset those value

row_len = 0

row_words = []

is_first_word = True

return ret

python-algorithms/algorithms/strings/text_justification.py at master · ilyvsc/python-algorithms · GitHub

Expand file tree

Breadcrumbs

text_justification.py

Latest commit

History

Breadcrumbs

text_justification.py

File metadata and controls