Given an array of strings 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 does 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.
Test Cases
Example 1:
Input: words = ["This", "is", "an", "example", "of", "text", "justification."], maxWidth = 16
Output:
[
"This is an",
"example of text",
"justification. "
]
Example 2:
Input: words = ["What","must","be","acknowledgment","shall","be"], maxWidth = 16
Output:
[
"What must be",
"acknowledgment ",
"shall be "
]
Explanation: Note that the last line is "shall be " instead of "shall be", because the last line must be left-justified instead of fully-justified.
Note that the second line is also left-justified becase it contains only one word.
Example 3:
Input: words = ["Science","is","what","we","understand","well","enough","to","explain","to","a","computer.","Art","is","everything","else","we","do"], maxWidth = 20
Output:
[
"Science is what we",
"understand well",
"enough to explain to",
"a computer. Art is",
"everything else we",
"do "
]
Solution
class Solution {
public List<String> fullJustify(String[] words, int maxWidth) {
int left = 0; List<String> result = new ArrayList<>();
while (left < words.length) {
int right = findRight(left, words, maxWidth);
result.add(justify(left, right, words, maxWidth));
left = right + 1;
}
return result;
}
private int findRight(int left, String[] words, int maxWidth) {
int right = left;
int sum = words[right++].length();
while (right < words.length && (sum + 1 + words[right].length()) <= maxWidth)
sum += 1 + words[right++].length();
return right - 1;
}
private String justify(int left, int right, String[] words, int maxWidth) {
if (right - left == 0) return padResult(words[left], maxWidth);
boolean isLastLine = right == words.length - 1;
int numSpaces = right - left;
int totalSpace = maxWidth - wordsLength(left, right, words);
String space = isLastLine ? " " : blank(totalSpace / numSpaces);
int remainder = isLastLine ? 0 : totalSpace % numSpaces;
StringBuilder result = new StringBuilder();
for (int i = left; i <= right; i++)
result.append(words[i])
.append(space)
.append(remainder-- > 0 ? " " : "");
return padResult(result.toString().trim(), maxWidth);
}
private int wordsLength(int left, int right, String[] words) {
int wordsLength = 0;
for (int i = left; i <= right; i++) wordsLength += words[i].length();
return wordsLength;
}
private String padResult(String result, int maxWidth) {
return result + blank(maxWidth - result.length());
}
private String blank(int length) {
return new String(new char[length]).replace('\0', ' ');
}
}