0449-serialize-and-deserialize-bst.js

/**
 * Serialize And Deserialize Bst
 * Time Complexity: O(N)
 * Space Complexity: O(N)
*/
var serialize = function (root) {
  if (!root) {
    return '';
  }

  const outputCollection = [];

  function treeTraversal(nodeElement) {
    if (!nodeElement) {
      return;
    }
    outputCollection.push(nodeElement.val);
    treeTraversal(nodeElement.left);
    treeTraversal(nodeElement.right);
  }

  treeTraversal(root);
  return outputCollection.join(',');
};

var deserialize = function (data) {
  if (!data) {
    return null;
  }

  const numericalSegments = data.split(',').map(Number);

  function treeBuilder(currentValues, minimumBound, maximumBound) {
    if (currentValues.length === 0) {
      return null;
    }

    let candidateValue = currentValues[0];
    if (candidateValue < minimumBound || candidateValue > maximumBound) {
      return null;
    }

    let extractedValue = currentValues.shift();
    let treeNodeInstance = new TreeNode(extractedValue);

    treeNodeInstance.left = treeBuilder(currentValues, minimumBound, extractedValue);
    treeNodeInstance.right = treeBuilder(currentValues, extractedValue, maximumBound);

    return treeNodeInstance;
  }

  return treeBuilder(numericalSegments, Number.MIN_SAFE_INTEGER, Number.MAX_SAFE_INTEGER);
};