Wrap text to a label width
A shipping label printer takes a fixed number of characters per line, and a description has to be broken across lines without splitting words.
- Fill each line greedily: keep adding words while they still fit.
- Words are separated by whitespace and joined back with a single space.
- A word longer than the whole width goes on a line of its own, unbroken.
- A width of zero or less, or text with no words, gives an empty list.
wordWrap(text: string, width: int) → list<string>
Go needs a compiler and Drill does not host one yet, so this page is the reference rather than an exercise: the problem, worked examples, and the solution in full. To type it out, the same problem runs in Python.
Where you start
func wordWrap(text string, width int) []string {
}Worked examples
| Call | Result |
|---|---|
wordWrap("the quick brown fox", 10) | []string{"the quick", "brown fox"} |
wordWrap("a bb ccc", 3) | []string{"a", "bb", "ccc"} |
wordWrap("supercalifragilistic is long", 5) | []string{"supercalifragilistic", "is", "long"} |
wordWrap("one two", 20) | []string{"one two"} |
Hint
Track the current line as a string. Before adding a word, check whether the line plus a space plus the word still fits.
Reference solution in Go
func wordWrap(text string, width int) []string {
lines := []string{}
if width <= 0 {
return lines
}
line := ""
for _, w := range strings.Fields(text) {
switch {
case line == "":
line = w
case len(line)+1+len(w) <= width:
line += " " + w
default:
lines = append(lines, line)
line = w
}
}
if line != "" {
lines = append(lines, line)
}
return lines
}