Cracking the Coding Interview, 4 Edition - 150 Programming Interview Questions and Solutions

Solutions to Chapter 20 | Hard
17 }
18 }
19 }
20 return null;
21 }
22
23 private Rectangle makeRectangle(int length, int height) {
24 if (groupList[length - 1] == null ||
25 groupList[height - 1] == null) {
26 return null;
27 }
28 if (trieList[height - 1] == null) {
29 LinkedList words = groupList[height - 1].getWords();
30 trieList[height - 1] = new Trie(words);
31 }
32 return makePartialRectangle(length, height,
33 new Rectangle(length));
34 }
35
36 private Rectangle makePartialRectangle(int l, int h,
37 Rectangle rectangle) {
38 if (rectangle.height == h) { // Check if complete rectangle
39 if (rectangle.isComplete(l, h, groupList[h - 1])) {
40 return rectangle;
41 } else {
42 return null;
43 }
44 }
45
46 // Compare columns to trie to see if potentially valid rect */
47 if (!rectangle.isPartialOK(l, trieList[h - 1])) return null;
48
49 for (int i = 0; i < groupList[l-1].length(); i++) {
50 Rectangle org_plus =
51 rectangle.append(groupList[l-1].getWord(i));
52 Rectangle rect = makePartialRectangle(l, h, org_plus);
53 if (rect != null) {
54 return rect;
55 }
56 }
57 return null;
58 }
NOTE: See code attachment for full code.
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Cracking the Coding Interview | Additional Review Problems