Examples with TreeNode com.pkumar7.TreeNode used on opensource projects

Example 61 with TreeNode

use of com.pkumar7.TreeNode in project TNTConcept by autentia.

the class MenuBean method openNode.

/**
 * Add non-leaf node to current node if it is accesible by current user
 * @param path path of current node
 * @param creds current user
 * @param neededRole role needed to render the node
 * @param parent parent node
 * @param cmd command name
 * @return true if node has been created
 */
private boolean openNode(Stack<TreeNode> path, Principal creds, GrantedAuthority neededRole, String cmd) {
    boolean added = false;
    if (neededRole == null || creds.hasAuthority(neededRole)) {
        String text;
        try {
            text = msg.getString("menu." + cmd);
        } catch (MissingResourceException e) {
            text = "MISSING : " + cmd + " : MISSING";
        }
        TreeNode child = new TreeNodeBase("folder", text, cmd, false);
        path.peek().getChildren().add(child);
        path.push(child);
        added = true;
    }
    log.debug("openNode - " + (added ? "OPEN  " : "IGNORE") + ": " + cmd);
    return added;
}

Example 62 with TreeNode

use of com.pkumar7.TreeNode in project interview by dqnn.

the class _1028RecoverATreeFromPreorderTraversal method recoverFromPreorder_Best.

/*
1028. Recover a Tree From Preorder Traversal
We run a preorder depth first search on the root of a binary tree.

At each node in this traversal, we output D dashes (where D is 
the depth of this node), then we output the value of this node.  
(If the depth of a node is D, the depth of its immediate child 
is D+1.  The depth of the root node is 0.)

If a node has only one child, that child is guaranteed to be 
the left child.

Given the output S of this traversal, recover the tree and 
return its root.

Input: "1-2--3---4-5--6---7"
Output: [1,2,5,3,null,6,null,4,null,7]
*/
// thinking process: O(n)/O(n) n = s.length()
// given a string, preorder visit this tree, and we form a dash as level,
// level 1 is 1 dash, level 2 is two dashes, if there is only node, that node is
// guaranteed as left child, return the root of the tree
// the difficulty of this problem is we have 2 dimensions problems,
// the sequence is only pre-ordered, and we have dashes to show which level it is
// so we need a structure to store levels where we are
// so we use a stack to store visited node,
public TreeNode recoverFromPreorder_Best(String s) {
    if (s == null || s.length() < 1)
        return null;
    int level = 0, var = 0;
    Stack<TreeNode> stack = new Stack<>();
    for (int i = 0; i < s.length(); ) {
        for (level = 0; s.charAt(i) == '-'; i++) level++;
        for (var = 0; i < s.length() && s.charAt(i) != '-'; i++) {
            var = var * 10 + (s.charAt(i) - '0');
        }
        // 
        while (stack.size() > level) {
            stack.pop();
        }
        TreeNode node = new TreeNode(var);
        if (!stack.isEmpty()) {
            if (stack.peek().left == null) {
                stack.peek().left = node;
            } else {
                stack.peek().right = node;
            }
        }
        stack.add(node);
    }
    while (stack.size() > 1) {
        stack.pop();
    }
    return stack.pop();
}

Example 63 with TreeNode

use of com.pkumar7.TreeNode in project interview by dqnn.

the class _107BinaryTreeLevelOrderTraversalII method levelOrderBottom3.

// reverse the result
public List<List<Integer>> levelOrderBottom3(TreeNode root) {
    List<List<Integer>> res = new ArrayList<>();
    if (null == root) {
        return res;
    }
    Queue<TreeNode> queue = new LinkedList<>();
    queue.offer(root);
    while (!queue.isEmpty()) {
        List<Integer> list = new ArrayList<>();
        int len = queue.size();
        for (int i = 0; i < len; i++) {
            TreeNode node = queue.poll();
            list.add(node.val);
            if (null != node.left) {
                queue.offer(node.left);
            }
            if (null != node.right) {
                queue.offer(node.right);
            }
        }
        res.add(list);
    }
    Collections.reverse(res);
    return res;
}

Example 64 with TreeNode

use of com.pkumar7.TreeNode in project interview by dqnn.

the class _1008ConstructBinarySearchTreeFromPreorderTraversal method bstFromPreorder_iterative.

public TreeNode bstFromPreorder_iterative(int[] preorder) {
    if (preorder == null || preorder.length == 0) {
        return null;
    }
    Stack<TreeNode> stack = new Stack<>();
    TreeNode root = new TreeNode(preorder[0]);
    stack.push(root);
    for (int i = 1; i < preorder.length; i++) {
        TreeNode node = new TreeNode(preorder[i]);
        if (preorder[i] < stack.peek().val) {
            stack.peek().left = node;
        } else {
            TreeNode parent = stack.peek();
            while (!stack.isEmpty() && preorder[i] > stack.peek().val) {
                parent = stack.pop();
            }
            parent.right = node;
        }
        stack.push(node);
    }
    return root;
}

Example 65 with TreeNode

use of com.pkumar7.TreeNode in project interview by dqnn.

the class _1008ConstructBinarySearchTreeFromPreorderTraversal method helper.

private TreeNode helper(int[] A, int max) {
    if (idx == A.length || A[idx] > max)
        return null;
    TreeNode root = new TreeNode(A[idx++]);
    root.left = helper(A, root.val);
    root.right = helper(A, max);
    return root;
}