private TreeNode buildTree(int[] inorder, int[] preorder, int start, int end) {
if (end < start) {
return null;
}
TreeNode root = new TreeNode(preorder[preIndex++]);
if (start == end) {
return root;
}
int inIndex = search(inorder, start, end, root.val);
root.left = buildTree(inorder, preorder, start, inIndex - 1);
root.right = buildTree(inorder, preorder, inIndex + 1, end);
return root;
}
public static void main(String[] args) {
TreeNode root = new TreeNode(1);
root.left = new TreeNode(2);
root.right = new TreeNode(2);
root.left.left = new TreeNode(3);
root.left.right = new TreeNode(3);
root.right.left = new TreeNode(4);
root.right.right = new TreeNode(3);
List<List<Integer>> res = levelOrder(null);
for (List<Integer> r : res) {
for (int i : r) {
System.out.print(i + "\t");
}
System.out.println();
}
}
private List<TreeNode> generate(int start, int end) {
List<TreeNode> list = new ArrayList<TreeNode>();
if (start <= end) {
for (int i = start; i <= end; i++) {
List<TreeNode> left = generate(start, i - 1);
List<TreeNode> right = generate(i + 1, end);
int leftSize = left.size();
int rightSize = right.size();
for (int p = 0; p < leftSize; p++) {
for (int q = 0; q < rightSize; q++) {
TreeNode node = new TreeNode(i);
node.left = left.get(p);
node.right = right.get(q);
list.add(node);
}
}
}
} else list.add(null);
return list;
}
public static void main(String[] args) {
ConstructBinaryTreeFromPreorderAndInorderTraversal obj =
new ConstructBinaryTreeFromPreorderAndInorderTraversal();
TreeNode result = obj.buildTree(new int[] {2, 1, 3, 4}, new int[] {1, 2, 3, 4});
System.out.println(result.toString());
}
public static void main(String[] args) {
TreeNode t1 = new TreeNode(5);
TreeNode t2 = new TreeNode(4);
TreeNode t3 = new TreeNode(8);
TreeNode t4 = new TreeNode(11);
TreeNode t5 = new TreeNode(13);
TreeNode t6 = new TreeNode(4);
TreeNode t7 = new TreeNode(7);
TreeNode t8 = new TreeNode(2);
TreeNode t9 = new TreeNode(1);
t1.left = t2;
t1.right = t3;
t2.left = t4;
t3.left = t5;
t3.right = t6;
t4.left = t7;
t4.right = t8;
t6.right = t9;
System.out.println(levelOrderBottom(t1));
}