代碼1

Runtime: 1 ms, faster than 52.72% of Java online submissions for Text Justification.

class Solution {
    public List<String> fullJustify(String[] words, int maxWidth) {
        int left = 0;
        List<String> list = new ArrayList();
        while (left < words.length) {
            int right = findRight(left, words, maxWidth);
            list.add(justify(left, right, words, maxWidth));
            left = right + 1;
        }
        return list;
    }
    public int findRight(int left, String[] words, int maxWidth) {
        int right = left + 1;
        int sum = words[left].length();
        while (right < words.length && 
               (sum + words[right].length() + 1 <= maxWidth)) {
            sum += words[right++].length() + 1;
        }
        return right - 1;
    }
    public String justify(int left, int right, String[] words, int maxWidth) {
        if (right == left) return padResult(words[left], maxWidth);
        boolean isLastLine = right == words.length - 1;
        int numSpace = right - left;
        int totalSpace = maxWidth - wordsLength(left, right, words);
        String space = isLastLine ? " " : blank(totalSpace / numSpace);
        int remainder = isLastLine ? 0 : totalSpace % numSpace;
        StringBuffer sb = new StringBuffer();
        for (int i = left; i <= right; i++) {
            sb.append(words[i]).append(space).append(remainder-- > 0 ? " " : "");
        }
        return padResult(sb.toString().trim(), maxWidth);
    }
    public int wordsLength(int left, int right, String[] words) {
        int res = 0;
        for (int i = left; i <= right; i++) {
            res += words[i].length();
        }
        return res;
    }
    public String padResult(String word, int maxWidth) {
        return word + blank(maxWidth - word.length());
    }
    public String blank(int length) {
        return new String(new char[length]).replace('\0',' ');
    }
}