Text Justification

 1 public class Solution {
 2     public ArrayList<String> fullJustify(String[] words, int L) {
 3         // IMPORTANT: Please reset any member data you declared, as
 4         // the same Solution instance will be reused for each test case.
 5         int wordsCount = words.length;
 6         ArrayList<String> result = new ArrayList<String>();
 7         int curLen = 0;
 8         int lastI = 0;
 9         for (int i = 0; i <= wordsCount; i++) {
10             if (i == wordsCount || curLen + words[i].length() + i - lastI > L) {
11                 StringBuffer buf = new StringBuffer();
12                 int spaceCount = L - curLen;
13                 int spaceSlots = i - lastI - 1;
14                 if (spaceSlots == 0 || i == wordsCount) {
15                     for(int j = lastI; j < i; j++){
16                         buf.append(words[j]);
17                         if(j != i - 1)
18                             appendSpace(buf, 1);
19                     }
20                     appendSpace(buf, L - buf.length());
21                 } else {
22                     int spaceEach = spaceCount / spaceSlots;
23                     int spaceExtra = spaceCount % spaceSlots;
24                     for (int j = lastI; j < i; j++) {
25                         buf.append(words[j]);
26                         if (j != i - 1)
27                             appendSpace(buf, spaceEach + (j - lastI < spaceExtra ? 1 : 0));
28                     }
29                 }
30                 result.add(buf.toString());
31                 lastI = i;
32                 curLen = 0;
33             }
34             if (i < wordsCount)
35                 curLen += words[i].length();
36         }
37         return result;
38     }
39 
40     private void appendSpace(StringBuffer sb, int count) {
41         for (int i = 0; i < count; i++)
42             sb.append(' ');
43     }
44 }