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

Example 21 with TreeNode

use of com.pkumar7.TreeNode in project Data-Structures-Algorithms by pankajgangwar.

the class JulyW1 method createBST.

TreeNode createBST(List<Integer> nums, int start, int end) {
    if (start > end) {
        return null;
    }
    int mid = (start + end) / 2;
    TreeNode root = new TreeNode(nums.get(mid));
    root.left = createBST(nums, start, mid - 1);
    root.right = createBST(nums, mid + 1, end);
    return root;
}

Example 22 with TreeNode

use of com.pkumar7.TreeNode in project Data-Structures-Algorithms by pankajgangwar.

the class JulyW1 method sortedListToBST.

/* LC : 109. Convert Sorted List to Binary Search Tree
    *  https://leetcode.com/problems/convert-sorted-list-to-binary-search-tree/
    * https://leetcode.com/problems/convert-sorted-array-to-binary-search-tree/
    *  Time : O(nlogn)
    */
public TreeNode sortedListToBST(ListNode head) {
    if (head == null)
        return null;
    if (head.next == null)
        return new TreeNode(head.val);
    ListNode mid = null;
    ListNode fast = head, slow = head;
    ListNode left = head, right = head;
    ListNode prevToMid = head;
    while (fast != null && fast.next != null) {
        fast = fast.next.next;
        prevToMid = slow;
        slow = slow.next;
    }
    mid = slow;
    if (mid != head) {
        prevToMid.next = null;
    } else {
        left = null;
    }
    right = mid.next;
    TreeNode root = new TreeNode(mid.val);
    root.left = sortedListToBST(left);
    root.right = sortedListToBST(right);
    return root;
}

Example 23 with TreeNode

use of com.pkumar7.TreeNode in project Data-Structures-Algorithms by pankajgangwar.

the class AprilW2 method findClosestLeaf.

/* https://leetcode.com/problems/closest-leaf-in-a-binary-tree/ */
public int findClosestLeaf(TreeNode root, int k) {
    HashMap<TreeNode, ArrayList<TreeNode>> map = new HashMap<>();
    buildGraph(root, null, map);
    TreeNode target = dfs(root, k);
    HashSet<TreeNode> visited = new HashSet<>();
    visited.add(target);
    Queue<TreeNode> q = new LinkedList<>();
    q.offer(target);
    while (!q.isEmpty()) {
        TreeNode curr = q.poll();
        if (curr.left == null && curr.right == null) {
            return curr.val;
        }
        for (TreeNode neig : map.get(curr)) {
            if (visited.contains(neig))
                continue;
            q.offer(neig);
            visited.add(neig);
        }
    }
    return -1;
}

Example 24 with TreeNode

use of com.pkumar7.TreeNode in project Data-Structures-Algorithms by pankajgangwar.

the class AprilW2 method dfs.

public TreeNode dfs(TreeNode root, int k) {
    if (root == null)
        return null;
    if (root.val == k)
        return root;
    TreeNode left = dfs(root.left, k);
    TreeNode right = dfs(root.right, k);
    if (left != null) {
        return left;
    } else {
        return right;
    }
}

Example 25 with TreeNode

use of com.pkumar7.TreeNode in project Data-Structures-Algorithms by pankajgangwar.

the class FebruaryW2 method countSmallerTree.

public List<Integer> countSmallerTree(int[] nums) {
    int n = nums.length;
    Integer[] res = new Integer[n];
    TreeNode root = null;
    for (int i = n - 1; i >= 0; --i) {
        root = insert(nums[i], root, res, i, 0);
    }
    return Arrays.asList(res);
}