public ArrayList<String> fullJustify(String[] words, int L) {

// base case

ArrayList<String> results = new ArrayList<String>();

if (words == null || words.length == 0 || (words.length == 1 && words[0] == "")) {

StringBuilder sb = new StringBuilder("");

while (L > 0) {

sb.append(" ");

L--;

}

results.add(sb.toString());

return results;

}

// transform

ArrayList<ArrayList<String>> t = new ArrayList<ArrayList<String>>();

ArrayList<String> line = new ArrayList<String>();

int lineLength = 0;

for (String word : words) {

if (lineLength + word.length() > L) {

t.add(new ArrayList<String>(line));

line.clear();

lineLength = 0;

}

line.add(word);

lineLength += word.length() + 1;

}

if (line.size() != 0)

t.add(line);

System.out.println(t);

// add extra space

for (int i = 0; i < t.size(); i++) {

ArrayList<String> l = t.get(i);

int size = l.size();

lineLength = getLineLength(l);

int extraSpace = L - lineLength;

int numSlot = size - 1;

StringBuilder sb = new StringBuilder("");

if (i != t.size() - 1) {

if (size == 1) {

sb.append(l.get(0));

int numSpace = L - lineLength;

while (numSpace > 0) {

sb.append(" ");

numSpace--;

}

} else {

for (int j = 0; j < size; j++) {

sb.append(l.get(j));

if (j != size - 1) {

// space

int numSpace = extraSpace / numSlot + (j < extraSpace % numSlot ? 1 : 0);

while (numSpace > 0) {

sb.append(" ");

numSpace--;

}

}

}

}

} else { // last line

for (int j = 0; j < size; j++) {

sb.append(l.get(j));

if (j != size - 1)

sb.append(" ");

}

int numSpace = L - lineLength - (size - 1);

while (numSpace > 0) {

sb.append(" ");

numSpace--;

}

}

results.add(sb.toString());

}

return results;

}

public int getLineLength(ArrayList<String> l) {

int length = 0;

for (String word : l) {

length += word.length();

}

return length;

}

public static void main(String[] args) {

TextJustification tj = new TextJustification();

String[] words = { "Listen", "to", "many,", "speak", "to", "a", "few." };//{"This", "is", "an", "example", "of", "text", "justification."};

System.out.println(tj.fullJustify(words, 6));

}