[Leetcode] Text Justification

Problem

Given an array of words and a length L, format the text such that each line has exactly L 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 L 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.

For example,
words: ["This", "is", "an", "example", "of", "text", "justification."]
L: 16.

Return the formatted lines as:

[
   "This    is    an",
   "example  of text",
   "justification.  "
]

Note: Each word is guaranteed not to exceed L in length.

Algorithm

We need to pack as many words as possible in each, until 

                                                wordLength + (nWords-1) + word[end] > L

There are three types of lines:

• Only one word, append word then append enough spaces, e.g. "justification "
• Last line, append word + " " for each word, except for the last word, then append enough spaces, e.g. "justification. "
• Other lines more than one words, append word + x spaces except for the last word, then append the last word, e.g.  "example of text"

Code