#101 LeetCode Symmetric Tree Iterative Javascript Solution

symmetricTreeIterative.js

var isSymmetric = function (root) {
  if (!root) {
    return "no tree was provided 🤔"; // return true
  }
  if (!root.left && !root.right) {
    return "you have a symmetric tree that only has 1 node...the root 🌱!"; // return true
  }
  let queue = [];
  queue.unshift(root);
  queue.unshift(root);
  let leftNode;
  let rightNode;
  while (queue.length) {
    console.log({ queue }); // check queue size to calculate space complexity. In symmetric tree can be num nodes +1
    console.log("running this code block"); // this will run at most for the total number of nodes in the tree
    leftNode = queue[0];
    queue.shift();
    rightNode = queue[0];
    queue.shift();
    if (leftNode.value !== rightNode.value) {
      return "your tree is not symmetric 🌴"; // return false
    }
    if (leftNode.left && rightNode.right) {
      queue.unshift(leftNode.left);
      queue.unshift(rightNode.right);
    } else if (leftNode.left || rightNode.right) {
      return "your tree is not symmetric 🌴"; // return false
    }
    if (leftNode.right && rightNode.left) {
      queue.unshift(leftNode.right);
      queue.unshift(rightNode.left);
    } else if (leftNode.right || rightNode.left) {
      return "your tree is not symmetric 🌴"; // return false
    }
  }
  return "you have a perfectly symmetric tree! 🌲"; //return true
};