Text Justification

Author: mengli

TextJustification.java

@@ -0,0 +1,59 @@
+import java.util.ArrayList;
+
+public class TextJustification {
+	public ArrayList<String> fullJustify(String[] words, int L) {
+		ArrayList<String> ret = new ArrayList<String>();
+		int length = words.length;
+		if (length == 0) return ret;
+		int start = 0, end = start;
+		int len = 0;
+		while (start < length) {
+			StringBuffer line = new StringBuffer();
+			while (end < length) {
+				int sl = words[end].length();
+				if (len + (end - start) + sl > L) {
+					break;
+				}
+				len += sl;
+				end++;
+			}
+			end--;
+			if (end < start) {
+				end = start;
+			}
+			if (start == end) {
+				line.append(words[start]);
+				int spaceCount = L - words[start].length();
+				for (int i = 0; i < spaceCount; i++) {
+					line.append(' ');
+				}
+				ret.add(line.toString());
+			} else {
+				boolean lastLine = end == length - 1;
+				int spaceBase = lastLine ? 1 : (L - len) / (end - start);
+				int bonus = lastLine ? 0 : L - len - spaceBase * (end - start);
+				line.append(words[start]);
+				for (int i = start + 1; i <= end; i++) {
+					for (int j = 0; j < spaceBase; j++) {
+						line.append(' ');
+					}
+					if (bonus > 0) {
+						line.append(' ');
+						bonus--;
+					}
+					line.append(words[i]);
+				}
+				if (lastLine) {
+					for (int i = 0; i < L - len - (end - start); i++) {
+						line.append(' ');
+					}
+				}
+				ret.add(line.toString());
+			}
+			start = end + 1;
+			end = start;
+			len = 0;
+		}
+		return ret;
+	}
+}