jianminchen

// https://leetcode.com/problems/construct-binary-search-tree-from-preorder-traversal/discuss/252479/Simple-Recursive-solution-in-Java-(more-verbose)
public TreeNode bstFromPreorder(int[] preorder) {
        return bstFromPreorder(preorder, 0, preorder.length - 1);
    }
    
    public TreeNode bstFromPreorder(int[] order, int start, int end) {
        if (start > end) {
            return null;
        }
        TreeNode node = new TreeNode(order[start]);

jianminchen

/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     public int val;
 *     public TreeNode left;
 *     public TreeNode right;
 *     public TreeNode(int x) { val = x; }
 * }
 */
public class Solution {

jianminchen

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution {

jianminchen

class Solution {
public:
    int longestOnes(vector<int>& A, int K) {
        int fr = 0, cnt = 0, ans = 0;
        for (int i = 0; i < A.size(); i++) {
            if (A[i] == 0)
                cnt++;
            while (cnt > K) {
                if (A[fr] == 0)
                    cnt--;

jianminchen

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace _996_number_of_squareful_arrays_II
{
    class Program

jianminchen

public static int countOneChildNode(Node node)
{
      if(node==null) return 0;

      return (((node.left!=null)!=(node.right!=null)? 1:0) + countOneChildNode(node.left) + countOneChildNode(node.right));
}

jianminchen

//post order
leftMoves  = getMoves(left) // 1
rightMoves = getMoves(right) // -1
ownMoves = node.val === 0? -1 : node.val // wrong
totalMoves = Math.abs(leftMoves) + Math.abs(rightMoves) // each node will be visted once - //moves from each edge 
return ownMoves + leftMoves + rightMoves // definition of recursive function

Example 4:
      4 
   /-2 -1\

jianminchen

// JavaScript source code
/**
 * Definition for a binary tree node.
 * function TreeNode(val) {
 *     this.val = val;
 *     this.left = this.right = null;
 * }
 */
/**
 * @param {TreeNode} root

jianminchen

/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     public int val;
 *     public TreeNode left;
 *     public TreeNode right;
 *     public TreeNode(int x) { val = x; }
 * }
 */
public class Solution {

jianminchen

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace _687_longest_univalue_path_IV
{
    public class TreeNode
    {