| 47 | class GfG { |
| 48 | |
| 49 | static Node buildTree(String str) { |
| 50 | |
| 51 | if (str.length() == 0 || str.charAt(0) == 'N') { |
| 52 | return null; |
| 53 | } |
| 54 | |
| 55 | String ip[] = str.split(" "); |
| 56 | // Create the root of the tree |
| 57 | Node root = new Node(Integer.parseInt(ip[0])); |
| 58 | // Push the root to the queue |
| 59 | |
| 60 | Queue<Node> queue = new LinkedList<>(); |
| 61 | |
| 62 | queue.add(root); |
| 63 | // Starting from the second element |
| 64 | |
| 65 | int i = 1; |
| 66 | while (queue.size() > 0 && i < ip.length) { |
| 67 | |
| 68 | // Get and remove the front of the queue |
| 69 | Node currNode = queue.peek(); |
| 70 | queue.remove(); |
| 71 | |
| 72 | // Get the current node's value from the string |
| 73 | String currVal = ip[i]; |
| 74 | |
| 75 | // If the left child is not null |
| 76 | if (!currVal.equals("N")) { |
| 77 | |
| 78 | // Create the left child for the current node |
| 79 | currNode.left = new Node(Integer.parseInt(currVal)); |
| 80 | // Push it to the queue |
| 81 | queue.add(currNode.left); |
| 82 | } |
| 83 | |
| 84 | // For the right child |
| 85 | i++; |
| 86 | if (i >= ip.length) break; |
| 87 | |
| 88 | currVal = ip[i]; |
| 89 | |
| 90 | // If the right child is not null |
| 91 | if (!currVal.equals("N")) { |
| 92 | |
| 93 | // Create the right child for the current node |
| 94 | currNode.right = new Node(Integer.parseInt(currVal)); |
| 95 | |
| 96 | // Push it to the queue |
| 97 | queue.add(currNode.right); |
| 98 | } |
| 99 | i++; |
| 100 | } |
| 101 | |
| 102 | return root; |
| 103 | } |
| 104 | |
| 105 | public static void main(String[] args) throws IOException { |
| 106 | BufferedReader br = |