068. Text Justification

Question 68

https://leetcode.com/problems/text-justification/

Given an array of words and a width maxWidth, format the text such that each line has exactly maxWidthcharacters 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 1:

Input:
words = ["This", "is", "an", "example", "of", "text", "justification."]
maxWidth = 16
Output:
[
   "This    is    an",
   "example  of text",
   "justification.  "
]

Answer

v1

class Solution(object):
    def fullJustify(self, words, maxWidth):
        """
        :type words: List[str]
        :type maxWidth: int
        :rtype: List[str]
        """
        current_string = ""
        Ans_list, current_list = [], []

        for word in words:
            if len(current_string) + len(word) + len(current_list) > maxWidth:
                if len(current_list) == 1:
                    Ans_list.append( current_list[0] + " "*(maxWidth - len(current_list[0])) )
                else:
                    rest_space = maxWidth - len(current_string)
                    split_space, begin_space = divmod( rest_space, len(current_list) - 1 )
                    current_string = (" "*(split_space+1)).join(current_list[:begin_space+1])
                    current_string += " "*(split_space)
                    current_string += (" "*(split_space)).join(current_list[begin_space+1:])
                    Ans_list.append(current_string)
                # clear all
                current_string = ""
                del current_list[:]
            # add new word
            current_list.append(word)
            current_string += word

        Ans_list.append( ' '.join(current_list) + ' '*(maxWidth - len(current_string) - len(current_list) + 1) )
        
        return Ans_list

v2

class Solution(object):
    def fullJustify(self, words, maxWidth):

        words_len = len(words)
        current_string = ""
        Ans_list = []
        current_words = 0
        current_list = []
        i = 0
        while i < words_len:
            if len(current_string) + len(words[i]) + 1 > maxWidth:
                if current_words == 1:
                    current_string += " "*(maxWidth - len(current_string))
                elif current_string == "":
                    current_string = words[i]
                    current_string += " "*(maxWidth - len(current_string))
                    i += 1
                else :
                    rest_space = maxWidth - len(current_string)
                    if not rest_space % (current_words - 1):
                        split_space = int(rest_space / (current_words - 1)) + 1
                        current_string = (" "*split_space).join(current_list)
                    else:
                        split_space = int( rest_space // (current_words - 1) ) + 1
                        begin_space = rest_space % (current_words - 1)
                        current_string = (" "*(split_space+1)).join(current_list[:begin_space+1])
                        current_string += " "*(split_space)
                        current_string += (" "*(split_space)).join(current_list[begin_space+1:])

                Ans_list.append(current_string)    
                current_string = ""
                current_words = 0
                del current_list[:]
            elif i == words_len -1 :
                current_list.append(words[i])
                current_string = " ".join(current_list)
                current_string += " "*(maxWidth - len(current_string))
                Ans_list.append(current_string)
                break
            else:
                current_list.append(words[i])
                current_string = " ".join(current_list)
                current_words += 1
                i += 1
        
        return Ans_list