Word Wrap

Write wrap(text, width) that breaks text into lines no longer than width characters and returns the lines as a list of strings.

• Words are the runs of characters that are not whitespace. A word is never split.
• Fill each line greedily: put the next word on the current line, after one space, if the line stays within width; otherwise start a new line with it.
• A word longer than width goes on a line of its own.
• Paragraphs are separated by blank lines (lines that are empty or hold only spaces). Wrap each paragraph separately and put an empty string between two paragraphs in the result. Inside a paragraph, single line breaks and runs of spaces count as one space.
• Paragraphs with no words are left out, so text with no words gives an empty list.

Examples

wrap('The quick brown fox jumps over the lazy dog', 10)
# returns ['The quick', 'brown fox', 'jumps over', 'the lazy', 'dog']
wrap('a supercalifragilistic word', 8)
# returns ['a', 'supercalifragilistic', 'word']
wrap('One two three.\n\nFour five.', 9)
# returns ['One two', 'three.', '', 'Four', 'five.']

Constraints

• 1 <= width <= 200
• text has at most 100,000 characters, and its only whitespace characters are spaces and \n.